Ontogeny of Psychomotor and Sensory Functions in the Rat: Effects of Sexual Dimorphism

Background: We studied the development of eight (8) different psychomotor and sensory functions in male and female rats, from postnatal day 10 to 45, with the aim of determining whether the ontogenesis of these functions was subject to sexual dimorphism. Methods: Wistar rats bred according to standard conditions in our laboratories were put into reproduction. Ten days after whelping, male and female pups were identified and subjected to a battery of behavioral tests on postnatal days 10, 15, 20, 25, 30 and 45, to assess the development of the following psychomotor and sensory functions: Exploratory activity, locomotor activity, emotional defecation, hind paws lifting reflex latency, wire-grasping time, Latencies of execution of crawling along the wire and of leap onto the ground, nociception (tail flick) and body weight. Results: Only complex brain functions generated by cerebral cortex activities, i.e. exploratory activity and leap execution latency, do not undergo differential development sex-dependent. However, voluntary motor functions initiated in the motor cortex, and requiring high peripheral muscle performance such as crawling execution latency and wire-grasping time developed more rapidly in males than in females. Correlatively, body weight i.e. muscle mass index increased more speedily in males than in females. On the other hand, studies of automatic motor functions such as locomotor activity, and reflex motor functions i.e. hind paws lifting reflex latency and tail flick latency showed earlier development in females than in males. In addition, the study of emotional response, an emanation of limbic structures, showed prodigious development in females compared to males. Conclusion: Our studies have shown that there is a developmental sexual dimorphism of the central nervous system in the rat. Indeed, studies of automatic and reflex motor functions, whose activities are essentially linked to the spinal cord and brainstem, indicated that hindbrain areas develop more speedily in females than in males. Likewise, study of the emotional response emanating from diencephalic limbic structures, in particular the hypothalamus, showed a prodigious and early development in females compared to males. Taken together, our studies indicate that the vast majority of brain structures and functions reached maturation earlier in females than in males. Estrogen is the trigger hormone for early maturation of the female brain.

Ontogeny and Metamorphic Patterns of Female Reproductive Organs of Ephedra sinica Stapf (Ephedraceae)

Ontogeny and metamorphic. development of female reproductive organs in Ephedra sinica Stapf were surveyed. At the end of April, female cones began to initialize from the vegetative buds. Pollination occurred in mid-May and seeds matured at the beginning of July. The ontogenetic pattern of female reproductive organs of E. sin ca is basically similar to that of E. distachya L. The foliar nature of the outer envelope of the ovule in Ephedra is corroborated. Reduction of ovule number as a tendency of speciation in the genus is substantiated by the occurrence of tri-ovulate cones coupled with comprehensive characters of the genus. The metamorphic patterns as well as the leaf nature of the outer envelope indicate that female cones of Ephedra are compound while the female reproductive units of the ovulate cone have been reduced from secondary reproductive shoots similar to those of cordaites by phylogenetic transformation, fusion and reduction. Each fertile bract together with its axillary female reproductive unit composed the Bract Scale and Seed Scale Complex of Ephedra.

Ontogeny of Immune Related Organs during Early Development of Carp (Cyprinus Carpio L.)

In this paper, ontogeny of immune-related organs during theearly development of carp was studied by histochemical technique-lcineBlue staining under acid conditions and PAS reaction(AB-PAS staining). Thekidney appeared one day before hatching, spleen, liver and pancreas emergedon the same day of hatching, and thymus was not found until the third day afterhatching. Ontogeny of these immune related organs of the carp in thisresearch is earlier than that reported by Botham.

Ontogeny,growth and development of the small intestine:Understanding pediatric gastroenterology

Throughout our lifetime,the intestine changes.Some alterations in its form and function may be genetically determined,and some are the result of adaptation to diet,temperature,or stress.The critical period programming of the intestine can be modified,such as from subtle differences in the types and ratios of n3:m6 fatty acids in the diet of the pregnant mother,or in the diet of the weanlings.This early forced adaptation may persist in later life,such as the unwanted increased intestinal absorption of sugars,fatty acids and cholesterol.Thus,the ontogeny,early growth and development of the intestine is important for the adult gastroenterologist to appreciate,because of the potential for these early life events to affect the responsiveness of the intestine to physiological or pathological challenges in later life.

Anatomy and ontogeny of unisexual flowers in dioecious Woonyoungia septentrionalis (Dandy) Law (Magnoliaceae)

Woonyoungia septentrionalis （Dandy） Law is aceae. The floral morphology and structure of the species a dioecious species with unisexual flowers in Magnoliare conspicuously different from other species and are important to the study of floral phylogeny in this family. The floral anatomy and ontogeny were investigated to evaluate the systematic position of W. septentrionalis, using scanning electron microscopy and light microscopy. All of the floral organs are initiated acropetally and spirally. The carpels are of conduplicated type without the differentiation of stigma and style. The degenerated stamens in the female flowers have the same structures as the normal stamens at the earlier developmental stages, but they do not undergo successive development and eventually degenerate. The male floral apex was observed to have the remnants of carpels in a few investigated samples. As the bisexual flower features could be traced both in the male and female flowers in W. septentrionalis, it suggests that the flower sex in Magnoliaceae tends toward unisexual. As well as the unisexual flowers, the reduced tepals and carpels and concrescence of carpels conform to the specialized tendency in Magnoliaceae, which confirms the derived position of W. septentrionalis in this family. As the initiation pattern of floral parts of W. septentrionalis is very similar to other species in this family, it needs further investigation and especially comparison with species in Kmeria to evaluate the separation of Woonyoungia.

Floral Ontogeny in Itea yunnanensis (Iteaceae)

To provide evidence insight into the phylogenetic position of Itea L., we observed floral ontogeny of Itea yunnanensis Franch. under the scanning electron microscope (SEM) for the first time. The floral phyllotaxis is whorled and floral organogenesis follows centripetal pattern. Sepal initiation is in a two_fifths helical order. Petal initiation appears simultaneous, and petals grow at an ordinary rate. The haplostemony of this species arises slightly later than petals but earlier than gynoecium in initiation. Two carpels are free at the early stage of floral ontogeny, but incurve, get closer and become appressed to each other later. Paraffin transverse sections series of gynoecium at anthesis show that two carpels are connate on the ventral side through their entire length. At last, two carpels within the ovary fuse completely, forming two locules separated by a septum, the ventral vascular bundles in two stylar lobes are connected through the parenchyma, and the stigma lobes become fused. These observations are different from those by Bensel and Palser (1975). The gynoecia they described might be not mature, but rather at early developmental stage. We compared floral developmental pattern and floral structure of Itea with its related taxa. In I. yunnanensis petals grow in the way that is different from that of some related taxa such as Saxifragaceae sensu stricto, Hydrangeaceae, Ribes, Brexia . The developing pattern of gynoecium in I. yunnanensis is similar to that of some members in the Saxifragaceae sensu stricto and Hydrangeaceae. The treatment to raise taxonomic rank of Itea from genus to family, Iteaceae, is supported by our results.

Ontogeny of the Traumatocrinus hsui

It is suggested that the characters of Traumatocrinus hsui Mu infants change remarkably in different ages;however,the characters of adult individuals are comparatively stable.The present study examined specimens of infant and adult individuals of T.hsui.Based on these observations,the authors divided the ontogeny of T.hsui into four infant stages（infant stageⅠ-Ⅳ）and one adult stage.In addition,the characters of the anal pyramid are supplemented and the infrabasal plates of T.hsui are confirmed in the present paper for the first time.

Ontogeny of the Lymphoid Organs of Japanese Flounder,Paralichthys olivaceus

Histological study on the ontogeny of the lymphoid organs, kidney, thymus and spleen of Japanese flounder, Paralichthys olivaceus, from hatching to 40 d was carried out. The pronephric kidney duct appeared early in hatching although the primordial haemopoietic stem cells were observed within a week after hatching. The spleen was first seen after 8 d of hatching. The thymus appeared after 15 d, situated near the pronephric kidney. Small lymphoid cells appeared during the later phase of the post-larval stage in the sequence of thymus, kidney and spleen. During the 40 d of observations, there were no distinct inner or outer zones in thymus and no red or white pulp in spleen. These results suggest that the nonspecific defense immune system plays a very important role in the early larval stage of Japanese flounder.

Ontogeny of expression of transforming growth factor-βand its receptors and their possible relationship with scarless or scar-forming healing in human fetal and postnatal skins

Fetal eutaneous wounds that oeeur in earlygestation heal without sear formation.Althoughmueh work has been done to eharaeterize the roleof transforming growth

Ontogeny of immune organs during early development stage of P. crocea

A histological and ultrastructural study was performed on the development of the head kidney, thymus, and spleen in Pseudosciaena crocea aging in range from just hatching to the 60th day after hatching （DAH）. Head kidney was first present on the 3rd DAH. Primordial haemopoietic stem cells were first observed in the head kidney which rapidly differentiate into different cellular types. Progenitor spleen was present on the 4th DAH, located close to the gut, which soon became rich in blood capillaries, red blood cells and thrombocytes. The thymus was obvious on the 4th DAH, and was located on either side of the upper comer of the opercular cavity, closely under the membrance of the opercuhr cavity. The thymus was the last lymphoid organ to appear but showed a quick development. This organ seemed to originate from haemopoietic stem cells migrating from the head region of the kidney. The thymus consisted of outer thymocytic and inner epithelioid zones. There was no obvious demarcation between them, but both zones were visible. Small lymphocytes appeared, or lymphoid organs become lymphoid, in the sequence thymus, head kidney and spleen. Only a small number of lymphocytes appeared in the later stages. Non-specific systems may play an important role in the immunocompetence mechanisms of P. crocea during its early development stage.

Ontogeny of the immune system in rock bream Oplegnathus fasciatus

Histogenesis of the immune system and specific activity of superoxide dismutase(SOD) were studied in rock bream Oplegnathus fasciatus from fertilization to 50 days after hatching(DAH).The pronephric tubule primordium developed in the embryo,14 h 30 min post fertilization.The spleen anlage was observed between the swim bladder and the intestine at 5 DAH,and the thymus was formed as a paired structure under the pharyngeal epithelium above the gill arch at 10 DAH.The order of the immune organs becoming lymphoid was the pronephric kidney(10 DAH),thymus(15 DAH) and spleen(21 DAH).As the embryo developed,the specific activity of SOD gradually increased until hatching,but subsequently SOD activity continuously decreased to a minimum at 14 DAH.After the spleen became lymphoid,the specific activity of SOD was relatively stable.It is suggested that the immaturity of the lymphoid organs and low specific activity of SOD was the cause of the high mortality of fingerlings 12 to 16 DAH.

What Can Al Learn from Psychology and When Can Al Neglectit?An Ontogeny-Free Study on the Cognition of Numerosity

AI has a long tradition of borrowing insights from psychology.There is also a voice of embracing ontogenetic elements in Al since ontogenetically earlier developing subsystems look easier to be the target of computational modeling.But due to be the fundamental difference between natural organisms and digital computers on the hardware level,this analogy does not always hold.For instance,as reported(Carey The origin of concepts,Oxford University Press,Oxford,2009a),(Carey in JP 106:220-254,2009b)ontogeny about the development of the cognitive mechanism cannot be smoothly mapped onto an AI context,although many of her psychologi-cal/philosophical insights,especially the indispensability of a quasi-phenomenologi-cal interface for manipulating numerical concepts,could still be kept.

Role of farnesoid X receptor in establishment of ontogeny of phase-I drug metabolizing enzyme genes in mouse liver

The expression of phase-I drug metabolizing enzymes in liver changes dramatically during postnatal liver maturation.Farnesoid X receptor(FXR) is critical for bile acid and lipid homeostasis in liver.However,the role of FXR in regulating ontogeny of phase-I drug metabolizing genes is not clear.Hence,we applied RNA-sequencing to quantify the developmental expression of phase-I genes in both Fxr-null and control(C57BL/6) mouse livers during development.Liver samples of male C57BL/6 and Fxr-null mice at6 different ages from prenatal to adult were used.The Fxr-null showed an overall effect to diminish the "day-1 surge" of phase-I gene expression,including cytochrome P450 s at neonatal ages.Among the 185 phase-I genes from 12 different families,136 were expressed,and differential expression during development occurred in genes from all 12 phase-I families,including hydrolysis: carboxylesterase(Ces),paraoxonase(Pon),and epoxide hydrolase(Ephx); reduction: aldoketo reductase(Akr),quinone oxidoreductase(Nqo),and dihydropyrimidine dehydrogenase(Dpyd); and oxidation: alcohol dehydrogenase(Adh),aldehyde dehydrogenase(Aldh),flavin monooxygenases(Fmo),molybdenum hydroxylase(Aox and Xdh),cytochrome P450(P450),and cytochrome P450 oxidoreductase(Por).The data also suggested new phase-I genes potentially targeted by FXR.These results revealed an important role of FXR in regulation of ontogeny of phase-I genes.

Floral Ontogeny of Two Species in Magnolia L.

Floral ontogeny is described in two species of genus Magnolia （Magnollaceae）, Magnolia alboserlcea Chun et C. Tsoong, and M. amoena Cheng, representing subgenus Magnolia and subgenus Yulani In Magnolia, by using scanning electron microscope （SEM）. The sequence of Initiation of floral organs Is from proximal to distal. The three distinct outermost and middle organs are Initiated in sequence, but ultimately form a single whorl, thus their ontogeny Is consistent with a sepal Interpretation. The last three tepals （petals） alternate with the preceding tepal whorl. The members of androeclum and gynoeclum arise spirally, although the androecium shows some Intermedlacy between a spiral and whorled arrangement. The carpel prlmordia initiate in group of four to five. The order of stamen Initiation within each tier Is not determined. The floral ontogeny Is remarkably homogeneous between the subgenus Magnolia and subgenus Yulani that does not support the resuming of genus Yulani.

Underwater Superoleophobic Crucian Fish Scale:Influence of Ontogeny on Surface Morphologies and Wettability

Recent development concerning underwater superoleophobic surface has been motivated by fish scales,which are rendered capable of preventing their surfaces from contamination in oil-polluted water.In this paper,for the first time,the variations in surface topography and chemical composition of crucian fish scales at different growth stages have been investigated.The water and oil contact angles,surface morphology and chemical composition of the fish scales were measured by means of contact angle measurements,scanning electron microscopy and Fourier transform infrared spectroscopy,respectively.It is found that surface morphology and chemical composition both have influences on surface wettability of fish scales;fish scale at infant period seems to possess better hydrophilicity than that of fish scales at mature and senescent period.What is more,it is believed that the wettability heavily depends on the surface structures during their growth procedure,which enlightens us to design and fabricate biomimetic multifunctional underwater superoleophobic surfaces inspired by nature.

Daily expression of sodium-dependent glucose cotransporter-1protein in jejunum during rat ontogeny

It is widely known that intestinal capacities such as the enzymatic hydrolysis of carbohydrates,lipids and proteins,and the subsequent absorption of the hydrolyzed products.are evolutionary matched to dietary loads and feeding behaviors.In this study,we demonstrate that the protein expression of apically located sodium-dependent glucose cotransporter-1(SGLT-1)throughout rat ontogeny is daily adjusted to afford glucose uptake when the load of this metabolically essential monosaccharide in the intestinal lumen is maximum.The jejunal expression of SGLT-1 protein in 14 one-day-old suckling pups was found to increase at dark and early light phase(P<0.05).when they have a better access to mother milk.In weaning21-d-old and juvenile 28-d-old rats,the cotransporter expression was high throughout the entire day(P<0.05).Finally,adult 90-d-old rats showed a well-developed circadian rhythm for SGLT-1 protein(P<0.05).whose expression increased at late light and dark phase when the highest intestinal glucose load was achieved.To our knowledge,these results are the first reporting the daily profile of SGLT-1 expression during rat early developmental stage and may contribute to understand the biological significance of a well-established molecular capacity to deal with the crucial increase of glucose load in the diet during the weaning process.

Ontogeny of Drosophila melanogaster female sex-appeal and cuticular hydrocarbons

The chemical communication system in Drosophila melanogaster Meigen,1830 plays a major role in courtship and consists of the male-specific cis-Vaccenyl acetate and sex-specific contact pheromones,cuticular hydrocarbons(CHC),which build up during ontogeny(first 4 days).They replace longer CHCs,common to both sexes and present only after the imaginal eclosion.A detailed quantitative description of the evolution of cuticular unsaturated hydrocarbons with age is presented here for males and females of different D.melanogaster strains,which have been bred in well controlled environments.Monoenes appear in both sexes at around 12 h,before female dienes.The present paper argues that this is likely linked to the switching on of a new set of genes.Ecdysone,which is more abundant in females than in males during this critical period,might control this switch.Parallel behavioral studies show that whereas female of all ages trigger early mature male courtship steps like wing vibration,only females older than 1 day trigger late courtship steps like attempted copulation.This supports the hypothesis that late male courtship steps might be triggered by the CHCs,which build up after this age,especially female-specific(Z,Z)-7,11-and(Z,Z)-5,9-dienes.

Ontogenetic Changes in Meristic Measurements of Silver Carp and Bighead Carp

The study analyzed 30 exterior meristic characters for 255 silver and bighead carp samples of 1- to 5-year-old collected from the National Primary Breeding Farm at Laojianghe Lake at the Middle Reach of the Yangtze River. Multivariate analysis was performed. In silver carp, the Euclidean distance was the greatest between the 1-year-old group and other age groups. Silver carp individuals were correctly classified at 98.0% accuracy with a discriminant function established by discriminant analysis based on meristic measurements. Similarly, bighead carp had the greatest distance between 1- to 2-year-old group and other age groups. Individuals of bighead carp were correctly classified at 90.7% accuracy by the discrimination function. The data showed that morphological transformation occurred during the life history of silver and bighead carp development. Eighteen meristic measurements showed highly significant differences, while four showed a significant difference between the two silver carp groups. Ten parameters decreased, while twelve measurements increased during development. In bighead carp, fourteen parameters were significantly different, while three parameters were significantly different between the two groups. Twelve parameters were significantly decreased and another five were increased during development. The results suggest allometric growth should be taken into account when identifying species, analyzing population differences and establishing germplasm standards based on morphology.

Pepsinogen C Gene Expression in Epithelial Cells of Rat Stomach During Development

Pepsinogens are zymogens of pepsins,aspecific proteases working as digestive enzymes in vertebrate stomach,of which biological and molecular properties have been extensively studied.Several exhaustive studies have been performed in the pepsinogen producing cells in developing rat stomachs,but little is known about the expression of pepsinogen gene in these cells.In this study,the ontogeny of pepsinogen producing cells in rat fundic glands was studied by in situ hybridization using a digoxigenin-labeled RNA probe.The rat gastric epithelium was stratified but was morphologically undifferentiated at the stage of 18.5 days of gestation.The pepsinogen mRNA was expressed both in chief cells and mucous neck cells in adult rats,which was first detected by in situ hybridization in the stomach of the rats at 3.5 days after birth.The development of pepsinogen producing cells could be classified into four stages:(1) 18.5 days of gestation to 0.5 day after birth;(2) 3.5 days to 2 weeks after birth;(3) 3～4 weeks after birth;(4) 8 weeks after birth.Pepsinogen expression is strictly limited to these cells,the distribution of which shown a developmental stage-specific manner.We concluded the pepsinogen C could offer excellent molecular markers of differentiation during stomach epithelial cellulur development.

An Adult Specimen of Hongshanosaurus houi (Dinosauria:Psittacosauridae) from the Lower Cretaceous of Western Liaoning Province, China

A new specimen consisting of a complete skull and lower jaw was discovered from the Lujiatun bed of the Lower Cretaceous Yixian Formation in the Lujiatun site, Beipiao, western Liaoning Province. It represents an adult specimen of Hongshanosaurus houi. Comparative studies show that Hongshanosaurus is distinguishable from its sister taxon Psittacosaurus by having the preorbital portion about half of the basal skull length, and the elliptical external naris, orbit, and a lower temporal fenestra oriented caudodorsally.