Gonadal dysgenesis in Turner syndrome with Y-chromosome mosaicism:Two case reports

BACKGROUND Turner syndrome(TS)has a variety of different karyotypes,with a wide range of phenotypic features,but the specific karyotype may not always predict the phenotype.TS with Y chromosome mosaicism may have mixed gonadal dysgenesis,and the mosaicism is related to the potential for gonadoblastoma.CASE SUMMARY In this case report,we report two cases of TS with different karyotypes and gonadal dysgenesis.Patient 1 had obvious virilization,and was positive for the SRY gene,but her karyotype in peripheral blood lymphocytes was 45X.Patient 2 had a mosaic karyotype,45X/46X,dic(Y:Y)(p11.3:p11.2),and the proportion of Y-bearing cells was 50%in peripheral blood lymphocytes,but the patient had normal female external genitalia and streaky gonads,with no genital virilism.Different tissues in the same TS individual may exhibit different ratios of mosaicism.The gonadal determination and differentiation of mosaic TS are primarily dependent on the predominant cell line in the gonads.CONCLUSION In TS patients with virilization,it is necessary to test at least two to three tissues to search for cryptic Y material.

Gonad traits and age structure of the sea urchin Heliocidaris crassispina in central range:a comparison with rangeextenders

The sea urchin Heliocidaris crassispina has northern expanded in geographic range to Toga Bay,Oga Peninsula in the Sea of Japan due to the global warming.To demonstrate the gonad traits and age structure of H.crassispina in the central range and compare the difference with those in northern extended range,we collected 100 H.crassispina individuals from a barren off Shitsumi,Fukui(central range),in August 2018.Their growth,gonad traits(size,development and color),and sex ratio were investigated and compared with those in Toga Bay,in August 2014(extended range).The successive 2012–2016 year classes of H.crassispina indicated successive juvenile recruitment in the central range,as found in the extended range.The individuals at three years old in central range were obviously larger than those in the extended range,showing large test diameter and body weight,possibly due to the higher temperature in central range than that in northern extended range.In addition,a balanced sex ratio in the central range was found,in contrast to the female-skewed sex ratio found in the extended range.Gonadal development was sex-and site-dependent.The testicular development in the central range was not only delayed in comparison to ovarian development,but also less delayed than those in the extended range,which possibly attribute to the higher water temperature in the central range.A significantly lower male gonad index and L*(lightness)value was recorded in central ranges compared to that in extended range,possibly due to the releasement of sperm of H.crassispina in central ranges.

A FAMILIAL 46 XY GONADAL DYSGENESIS AND HIGH INCIDENCE OF EMBRYONIC GONADAL TUMORS

The Swyer’s syndrome, 46XY gonadal dysgenesis ( 46XYGD) or XY female, belongs to the category of sexual abnomality. The syndrome is characterized by a female phenotype with streak gonads, 46XY karyotype and complicated by frequent develop of gonadal tumors. A congragated familial 46XYGD was analyzed. We have examined the whole family from many aspects and have followed the affected members more than 10 years. In present case , all eight siblings phenotypically were girls ; the two eldest members died between 1970 1972 from embryonic gonadal tumors. Five of remaining 6 girls were affected by the syndrome of 46 XYGD and two have got the same kind of tumor dysgerminoma. By cytogenetic and cytobiological studies and on the basis of accumulated data the mechanism of gonadal carcinogenesis was analyzed. The origin of dysgerminoma for 46XYGD syndrome was postulated.

A Case Report: Challenge in Treatment of a Rare Condition of Gonadal Agenesis and Bipolar Disease

Background: We report a rare case of congenital bilateral testicular agenesis who presented with a suicide attempt. We pose the question of testosterone therapy could improve his mental health. Case Report: A 36-year-old man was admitted to a psychiatric ward after the suicide attempt. An endocrinology consult is requested to address if hormone replacement therapy could improve his depression and future suicide attempts. His past medical history is significant for gonadal agenesis, testicular implants placement at age 16, bipolar type 1 diagnosed 2 years ago before the presentation. The patient received testosterone replacement treatment at age 13 - 15 years. Since that time, he has not been placed on any testosterone therapy. Physical exam revealed minimal axillary and pubic hair, testicular implants with a microphallus. Laboratory values reflect hypergonadotropic hypogonadism consistent with testicular agenesis. He was suicidal and testosterone treatment was deferred. Discussion: It is a rare case of congenital testicular agenesis with bipolar disorder which was resistant to therapy. The patient had profound hypogonadism, which needed testosterone replacement therapy. However, the therapy was deferred because of an acute psychotic condition. This case also highlights that there is no strong evidence of the effect of hormonal therapy on mental health in this group.

Higher Dietary Arachidonic Acid Levels Improved the Growth Performance, Gonad Development, Nutritional Value, and Antioxidant Enzyme Activities of Adult Sea Urchin(Strongylocentrotus intermedius)

The gonads of sea urchins(Strongylocentrotus intermedius) are characterized by high levels of arachidonic acid(ARA, 20:4 n-6) and eicosapentaenoic acid(EPA, 20:5 n-3). However, to our knowledge, little information is available regarding the physiological response of adult sea urchins to dietary ARA. In the present study, four dietary feeds were formulated with graded ARA(0, 0.5%, 1%, and 2% dry diet). Each diet was randomly allocated to three cages during a 56-day feeding experiment. The results showed that the sea urchin weight gain rate(WGR) and the gonadosomatic index(GI) significantly increased as ARA was equal to or above 1.0% of dry diet(P < 0.05). The activities of superoxide dismutase(SOD), catalase(CAT), and total anti-oxidative capacity(T-AOC) were the highest in the coelomic fluid of sea urchins that were fed diets with 1% ARA. The total essential amino acid(TEAA) and its ratio to total non-essential amino acid(TNEAA) showed a similar tendency to WGR and GI as dietary ARA increased, and the highest TEAA and TEAA/TNEAA were observed in the gonads of sea urchins that were fed diets with 1% ARA. Levels of ARA and ARA/EPA of the gonads increased while n-3/n-6 polyunsaturated fatty acid(PUFA) decreased with the increase of dietary ARA(P < 0.05). EPA in the gonads of experimental animals fed with formulated feeds showed no significant differences(P> 0.05), but was significantly lower than those fed with kelp(P < 0.05). These results suggested that relatively higher levels of ARA(1% dry diet) significantly promoted growth, gonad development, activities of antioxidant enzymes, as well as nutritional values(TEAA, TEAA/TNEAA, and PUFA) of adult S. intermedius.

The m6A methylation regulates gonadal sex differentiation in chicken embryo

Background:As a ubiquitous reversible epigenetic RNA modification,N6-methyladenosine(m6A)plays crucial regulatory roles in multiple biological pathways.However,its functional mechanisms in sex determination and differentiation during gonadal development of chicken embryos are not clear.Therefore,we established a transcriptome-wide m6A map in the female and male chicken left gonads of embryonic day 7(E7)by methylated RNA immunoprecipitation sequencing(MeRIP-seq)to offer insight into the landscape of m6A methylation and investigate the post-transcriptional modification underlying gonadal differentiation.Results:The chicken embryonic gonadal transcriptome was extensively methylated.We found 15,191 and 16,111 m6A peaks in the female and male left gonads,respectively,which were mainly enriched in the coding sequence(CDS)and stop codon.Among these m6A peaks,we identified that 1013 and 751 were hypermethylated in females and males,respectively.These differential peaks covered 281 and 327 genes,such as BMP2,SMAD2,SOX9 and CYP19A1,which were primarily associated with development,morphogenesis and sex differentiation by functional enrichment.Further analysis revealed that the m6A methylation level was positively correlated with gene expression abundance.Furthermore,we found that YTHDC2 could regulate the expression of sex-related genes,especially HEMGN and SOX9,in male mesonephros/gonad mingle cells,which was verified by in vitro experiments,suggesting a regulatory role of m6A methylation in chicken gonad differentiation.Conclusions:This work provided a comprehensive m6A methylation profile of chicken embryonic gonads and revealed YTHDC2 as a key regulator responsible for sex differentiation.Our results contribute to a better understanding of epigenetic factors involved in chicken sex determination and differentiation and to promoting the future development of sex manipulation in poultry industry.

Localization of nitric oxide synthase in the developing gonads of amphioxus Branchiostoma belcheri tsingtauense

The localization of nitric oxide synthases （NOS） is dealed with in the developing gonads of amphioxus Branchiostoma belcheri tsingtauense. It was found by NADPH-diaphorase staining that （1） NOS activity was present in the nuclear membranes of germinal vesicles during the entire period ofoocyte development; （2） NOS was localized in both the nuclear membranes and the perinuclear region of cytoplasm in the vitellogenetic oocytes; （3） NOS was relocated in the cortical layer in the mature egg; （4） NOS activity was present in spermatocytes, but not in the spermatogonia in the middle of October; （5） NOS was detected in both spermatozoa and spermatids as well as spermatocytes during the breeding season. This is the first report on the distribution pattern of NOS in the developing gonads in protochordates. These results suggest a role for NOS in the functioning of the nuclear membranes and yolk synthesis during oogenesis and in cell division and differentiation during spermatogenesis.

Effects of spectral composition,photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems(RAS)

Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P<0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P>0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.

Phenotypic correlations of somatic and gonad traits of sea urchins Glyptocidaris crenularis in two sampled periods:first insight into its breeding and aquaculture

Prior knowledge of the correlations among commercially important traits in Glyptocidaris crenularis can be used to guide development of breeding and aquaculture programs for this species.We evaluated the phenotypic correlations between somatic and gonadal traits in G.crenularis during two sample periods(October 2010 and April 2011).The coeffi cients of variation(CV%)for body weight(BW),redness(a*),yellowness(b*),gonad wet weight(GW),and gonad index(GI)were>20% in both periods,while those of other traits were very low.GW was signifi cantly correlated with somatic traits(diameter,height,and body weight)in both periods,although the correlation coeffi cients ranged from 0.473 to 0.636(P<0.01).Gonad moisture content(GC),a*,and lightness(L*)were not signifi cantly correlated with somatic traits(P>0.05).The color trait b* was negatively correlated with somatic traits(test diameter,test height,and body weight)during the period when the gonads were well developed(April 2011,P<0.05).We observed little difference in the nature of the phenotypic correlations between the two sample periods.The high variation in the somatic and gonad weight traits in G.crenularis suggests there is considerable potential for selective breeding.However,our results suggest that gonad quality traits cannot be selected indirectly by selecting for body weight.Our study provides an insight into the method for improving the breeding and aquaculture of G.crenulari.

WJSC 6^(th) Anniversary Special Issues(2):Mesenchymal stem cells Differentiation of mesenchymal stem cells into gonad and adrenal steroidogenic cells

Hormone replacement therapy is necessary for patients with adrenal and gonadal failure.Steroid hormone treatment is also employed in aging people for sex hormone deficiency.These patients undergo such therapies,which have associated risks,for their entire life.Stem cells represent an innovative tool for tissue regeneration and the possibility of solving these problems.Among various stem cell types,mesenchymal stem cells have the potential to differentiate into steroidogenic cells both in vivo and in vitro.In particular,they can effectively be differentiated into steroidogenic cells by expressing nuclear receptor 5A subfamily proteins(steroidogenic factor-1 and liver receptor homolog-1)with the aid of cAMP.This approach will provide a source of cells for future regenerative medicine for the treatment of diseases caused by steroidogenesis deficiencies.It can also represent a useful tool for studying the molecular mechanisms of steroidogenesis and its related diseases.

Recovery of gonadal development in tiger puffer Takifugu rubripes after exposure to 17β-estradiol during early life stages

The aim of the present study was to investigate the long-term effects of 17l）-estradiol （E2） exposure on gonadal development in the tiger puffer （Taktfugu rubripes）, which has a genetic sex determination system of male homogametic XY-XX. Tiger puffer larvae were exposed to 1, 10 and 100 μg/L E2 from 15 to 100 days post-hatch （dph） and then maintained in clean seawater until 400 dph. Changes in sex ratio, gonadal structure and gonadosomatic index （GSI） were monitored at 100, 160, 270 and 400 dph. Sex-associated single nucleotide polymorphism （SNP） markers were used to analyze the genetic sex of samples, except those at 100 dph. Exposure had a positive effect on the conversion of genetically male gonads into phenotypically female gonads at 100 dph. However, gonads from 60% of genetic XY males in the 1-μg/L E2 group and 100% in the 10-μg/L E2 group developed intersexual gonads at 160 dph; gonads of all genetic XY males in the two treatment groups reverted to testis by 270 dph. While 38%, 57% and 44% of gonads of XY fish in the 100-gg/L E2 group reverted to intersexual gonads at 160, 270 and 400 dph, respectively, none reverted to testis after E2 treatment. In addition, E2 exposure inhibited gonadal growth of both genetic sexes, as indicated by the clear dose-dependent decrease in GSI at 270 and 400 dph. The results showed that exposure to E2 during the early life stages of tiger puffer disrupted gonadal development, but that fish recovered after migration to clean seawater. The study suggests the potential use of tiger puffer as a valuable indicator species to evaluate the effects of environmental estrogens on marine fish, thereby protecting valuable fishery resources.

Anti-diabetic and anti-hyperlipidemic effects of sea cucumber(Cucumaria frondosa) gonad hydrolysates in type Ⅱ diabetic rats

The present study investigated the anti-diabetic activity and potential mechanisms of sea cucumber gonad hydrolysates(SCGH)in a rat model of type II diabetes induced by streptozotocin(STZ)combined with high-fat diet(HFD).Results showed that SCGH significantly reduced water intake,fasting blood glucose level and glycated hemoglobin level.Moreover,the oral glucose tolerance,insulin resistance and plasma lipid level in diabetic rats were also alleviated.Furthermore,histological analysis showed that SCGH effectively protected the tissue structure of liver.In addition,mechanism studies showed that SCGH improved glucose metabolism via activating the IRS/Akt signaling pathway,and promoted lipid metabolism via activating the AMPK signaling pathway.In summary,these findings suggested that SCGH have potential anti-diabetic effects by improving insulin resistance and lipid metabolism disorders.

Steroid sex hormone dynamics during estradiol-17β induced gonadal differentiation in Paralichthys olivaceus(Teleostei)

Steroid sex hormones, such as estradiol-17β （E2） and testosterone （T）, are important regulators of sex change in fish. In this study, we examined the effects of E2 treatment on the dynamics of E2 and T during gonadal differentiation in the olive flounder Paralichtbys olivaceus using histology and radioimmunoassay （RIA）. Flounder larvae were divided into five groups （G0~G4）, and fed with 0 （control）, 0.2, 2, 20 and 100 mg E2/kg feed from 35 to 110 day post hatching （dph）. Fish growth in the G1 and G2 groups was not significantly different from that of the control group （P〉0.05）, while fish in the G3 and G4 groups were less active and showed growth depression and high mortality. The gonads of fish in the G3 and G4 groups were smaller and surrounded by hyperplastic connective tissue. The frequency of females in the G0-G4 groups was 54.5%, 75.0%, 100%, 100% and 93.3%, respectively. The RIA analyses of E2 and T showed that T levels decreased during gonadal differentiation, and increased slightly at the onset of ovarian differentiation, while E2 levels increased gradually and peaked at the onset of ovarian differentiation in the control group. In the E2-treated groups, T levels decreased before the onset of ovarian differentiation. E2 levels were high on the 48 dph, but declined to a lower level on the 54 dph, and then increased gradually during gonadal differentiation. And a sharp increase of E2 levels were observed in all E2-treated groups at the onset of ovarian differentiation. The data suggest that T and E2 play important roles during gonadal differentiation, and an E2 dose of 2 mg/kg feed could induce sex reversal in P olivaceus.

Seasonal variations in gonad morphology and hypothalamic GnRH-I and GnIH in Eurasian Tree Sparrow,a multi-brooded passerine

The hypothalamic-pituitary-gonadal(HPG)axis ubiquitously regulates seasonal reproduction,following the rhythmicity of a suite of environmental cues.Birds display prominent seasonal variations in gonad size regulated by two hypothalamic peptides,gonadotropin-releasing hormone-1(GnRH-I)and gonadotropin-inhibiting hormone(GnIH).How multi-brooded avian species adjust GnRH-I and GnIH to regulate gonadal morphology seasonally remains largely unknown.Here,we studied the variations in the hypothalamic immunoreactivity(ir)of GnRH-I and GnIH,gonadal proliferation,and apoptosis in a typical multi-brooded species,the Eurasian Tree Sparrow(Passer montanus),across the pre-breeding(PB),first breeding(FB),second breeding(SB),pre-basic molt(PM),and wintering stages(WS).Our results showed that both sexes had higher preoptic area(POA)-GnRH-I-ir but lower paraventricular nucleus(PVN)-GnIH-ir neurons during the breeding stages(FB and SB)relative to other life-history stages,with no significant differences between two broods.The testes and ovaries were significantly larger during the breeding stages.Testicular volume increased during the two broods due to anincreased diameter of seminiferous tubules.Furthermore,there were more testicular apoptotic cells in PB and WS stages than in breeding stages,and in PB stage than in PM stage.Males had higher POA-GnRH-I expression than females during the breeding stages,but both sexes had comparable PVN-GnIH expression throughout the annual cycle.Both sexes of the sparrows may undergo a similar pattern of life-history stage-dependent variation in the hypothalamic GnRH-I,GnIH,and gonadal morphology,except that during breeding stages,males may display higher expression of POA-GnRH-I relative to females.The higher expression of POA-GnRH-I-ir in breeding male sparrows may be critical for male-dependent parental care.

Sex-Based Variation of Gene Expression in the Gonads and Fins of Russian Sturgeon (<i>Acipenser gueldenstaedtii</i>)

Russian sturgeon (Acipenser gueldenstaedtii) is a primitive freshwater fish and a source of black caviar. The genes involved in sexual determination and differentiation are still unknown and there are no molecular markers for sex identification in this species. Studying the variation of the sex-based differences in genomic sequences and in gene expression in the sturgeon may lead to markers of sex in early stages of development and advances in aquaculture, as well as provide novel insights about the evolution of reproduction, sex determination, and sexual differentiation mechanisms in vertebrates. Previous studies by our and other groups have identified differentially expressed genes in the gonads of adult female and male sturgeon. The current study aimed to test whether these genes were also differentially expressed in non-gonadal tissue, namely fins. We measured by qRT-PCR the mRNA levels of 29 known and novel sex-related genes in the gonads and fins of males (4 years old) and females (7 years old;sexual maturation is earlier in males than in females). Six genes (ATP6, IGFRM, LIA1A, S1A, NPL1A, GAPDH and SOX9) showed higher expression in female fins. However, only ATP6 mRNA levels differed in fins of males and females of the same age (4 years old). These findings underscore the impracticality of sex identification based on gene expression in non-gonadal tissue and the need for genetic sex markers in the Russian sturgeon.

Expression of hepatitis B virus surface antigens induces defective gonad phenotypes in Caenorhabditis elegans

AIM To test whether a simple animal, Caenorhabditis elegans(C. elegans), can be used as an alternative model to study the interaction between hepatitis B virus antigens(HBs Ag) and host factors. METHODS Three plasmids that were able to express the large, middle and small forms of HBs Ags(LHBs Ag, MHBs Ag, and SHBs Ag, respectively) driven by a ubiquitous promoter(fib-1) and three that were able to express SHBs Ag driven by different tissue-specific promoters were constructed and microinjected into worms. The brood size, egglaying rate, and gonad development of transgenic worms were analyzed using microscopy. Levels of m RNA related to endoplasmic reticulum stress, enpl-1, hsp-4, pdi-3 and xbp-1, were determined using reverse transcription polymerase reaction(RT-PCRs) in three lines of transgenic worms and dithiothreitol(DTT)-treated wild-type worms. RESULTS Severe defects in egg-laying, decreases in brood size, and gonad retardation were observed in transgenic worms expressing SHBs Ag whereas moderate defects were observed in transgenic worms expressing LHBs Ag and MHBs Ag. RT-PCR analysis revealed that enpl-1, hsp-4 and pdi-3 transcripts were significantly elevated in worms expressing LHBs Ag and MHBs Ag and in wild-type worms pretreated with DTT. By contrast, only pdi-3 was increased in worms expressing SHBs Ag. To further determine which tissue expressing SHBs Ag could induce gonad retardation, we substituted the fib-1 promoter with three tissue-specific promoters(myo-2 for the pharynx, est-1 for the intestines and mec-7 for the neurons) and generated corresponding transgenic animals. Moderate defective phenotypes were observed in worms expressing SHBs Ag in the pharynx and intestines but not in worms expressing SHBs Ag in the neurons, suggesting that the secreted SHBs Ag may trigger a cross-talk signal between the digestive track and the gonad resulting in defective phenotypes. CONCLUSION Ectopic expression of three forms of HBs Ag that causes recognizable phenotypes in transgenic worms suggests that C. elegans can be used as an alternative model for studying virus-host interactions because the resulting phenotype is easily detected through microscopy.

Comparative Study of the Growth and Gonad Development of Clarias gariepinus （Burchell 1822） Fed Diets with Plant and Animal-based Ingredients in Concrete Tanks

A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus with an average weight of 205 ×5.09 g, were stocked in six concrete tanks （9 × 4 × 2 m3） containing 20 fish each. Experiment had 3 replicates and animals fed daily at 5% body weights. There was no significant difference （P 〈 0.05） in proximate compositions of the two experimental feeds and controls. Fecundity, gonad weight and gonasomatic index were higher in fish fed diet 13 than A and C. Similarly, growth indices were higher in fish fed diet B than in A and C. Histology of gonads showed a faster development of oocytes of eggs in fish fed animal-based ingredients than plant-based and combined plant and animal diets. Although there were slight differences in growth parameters and gonad development in favor of feed with animal-based ingredients, plant-based feed compared favorably in the growth and gonad development of C. gariepinus. Plant-based ingredients are recommended on the basis of affordability and availability as substitute for animal-based ingredients in C. gariepinus feed.

Annual change of the gonadal development of the amphioxus in Xiamen

The study was made by observing the annual change of the gonadal development of amphioxus in Xiamen cohtinuously for two years from November, 1986 to November, 1988. We determined the gonadal diameter, gonadosomatic index of each amphioxus, and observed the histological characteristic of the gonadal development of the female and male by cut section, which provided the basis for dividing the stages gonads and the determining level of the gonadal development of amphioxus in each month.

Expression Characteristics of Odf3 in Gonad Are Different Between Chlamys farreri and Vertebrates

Outer dense fibers are specific subcellular components of mammal sperm flagella, apart from the axoneme and its associated proteins. As one of the outer dense fibers components, ODF3 is essential for the formation of mammal sperm flagella. In the present study, we isolated the Odf3 gene, 1033 bp in length, from Zhikong scallop Chlamys farreri, which was named as Cf-Odf3. It was predicted that Cf-Odf3 encodes a protein of 240 amino acids which contains 5 discontinuous Pro-Gly-Pro repeats. The Cf-Odf3 transcripts were detected in both testis and ovary of C. farreri at various stages through q RT-PCR. The Cf-ODF3 protein synthesized by prokaryotes was purified using Ni^(2+)-NTA affinity chromatography and used to produce its polyclonal antibody. The antibody product was effective and specific as was examined by Western blotting. The Cf-Odf3 transcript and Cf-ODF3 protein were located in intragonadal somatic cells(ISCs), spermatogonia and spermatocytes of C. farreri testes, while no transcription of Cf-Odf3 and synthesis of Cf-ODF3 were detected in spermatids and spermatozoa. The location of Odf3 expression is different from that of vertebrates where ODF3 is synthesized specifically in spermatids and sperm flagella. Moreover, the Cf-Odf3 expression was also detected in ISCs, oogonia and oocytes of the scallop ovaries. Our finding revealed a different characteristic of Odf3 expression between scallop and vertebrates, which implied that Cf-Odf3 played a role in the gametogenesis of C. farreri.

METHOD FOR OBSERVATION OF DEEMBEDDED SECTIONS OF FISH GONAD BY SCANNING ELECTRON MICROSCOPY

This article reports a method for examining the intracellular structure of fish gonads using a scanning electron microscope(SEM). The specimen preparation procedure is similar to that for transmission electron microscopy wherein samples cut into semi thin sections are fixed and embedded in plastic. The embedment matrix was removed by solvents. Risen free specimens could be observed by SEM. The morphology of matured sperms in the gonad was very clear, and the oocyte internal structures appeared in three dimensional images. Spheroidal nucleoli and yolk vesicles and several bundles of filaments adhered on the nucleoli could be viewed by SEM for the first time.