Genetic gain and inbreeding from simulation of different genomic mating schemes for pig improvement

Background Genomic selection involves choosing as parents those elite individuals with the higher genomic estimated breeding values(GEBV)to accelerate the speed of genetic improvement in domestic animals.But after multi-generation selection,the rate of inbreeding and the occurrence of homozygous harmful alleles might increase,which would reduce performance and genetic diversity.To mitigate the above problems,we can utilize genomic mating(GM)based upon optimal mate allocation to construct the best genotypic combinations in the next generation.In this study,we used stochastic simulation to investigate the impact of various factors on the efficiencies of GM to optimize pairing combinations after genomic selection of candidates in a pig population.These factors included:the algorithm used to derive inbreeding coefficients;the trait heritability(0.1,0.3 or 0.5);the kind of GM scheme(focused average GEBV or inbreeding);the approach for computing the genomic relationship matrix(by SNP or runs of homozygosity(ROH)).The outcomes were compared to three traditional mating schemes(random,positive assortative or negative assortative matings).In addition,the performance of the GM approach was tested on real datasets obtained from a Large White pig breeding population.Results Genomic mating outperforms other approaches in limiting the inbreeding accumulation for the same expected genetic gain.The use of ROH-based genealogical relatedness in GM achieved faster genetic gains than using relatedness based on individual SNPs.The GROH-based GM schemes with the maximum genetic gain resulted in 0.9%-2.6%higher rates of genetic gainΔG,and 13%-83.3%lowerΔF than positive assortative mating regardless of heritability.The rates of inbreeding were always the fastest with positive assortative mating.Results from a purebred Large White pig population,confirmed that GM with ROH-based GRM was more efficient than traditional mating schemes.Conclusion Compared with traditional mating schemes,genomic mating can not only achieve sustainable genetic progress but also effectively control the rates of inbreeding accumulation in the population.Our findings demonstrated that breeders should consider using genomic mating for genetic improvement of pigs.

Protective Effect of Silent Mating Type Information Regulation 2 Homolog 1 on TGF-β1 Pathway via mTOR in Diabetic Nephropathy

Objective: To demonstrate whether the expression of silent mating type information regulation 2 homolog 1 (SIRT1) affects the level of TGF-β1 and Smad3 in HEK293 cells through regulating mTOR. Methods: First, recombinant plasmids DNA (rSIRT1) and siRNA targeting SIRT1 were constructed which were transfected into Human Embryonic Kidney 293 cell (HEK293) cells, respectively. Then, the generation of intracellular ROS in cells was examined by flow cytometry using the oxidation-sensitive probe. Last, the expressions of TGF-β1, smad3, P53, mTOR, p-mTOR, LC3-I and LC3-II in cells were detected to observe the effect of SIRT1 on TGF-β1 Pathway by western blot analysis. Results: We demonstrated that overexpressing of SIRT1 may decrease TGF-β1 and Smad3 expression in HEK293 cells through regulating mTOR. In addition, the result is the opposite when SIRT1 was silent in HEK293 cells. Conclusions: SIRT1 is closely related to TGF-β1/Smad3 pathway that correlates with the regulation of mTOR and ROS generation and causes diabetic nephropathy. The available evidence implies that SIRT1 has great potential as a clinical target for the prevention and treatment of renal fibrosis in the development of DN.

The Effect of Attendance Patterns on the Lek Mating System in the Omei Treefrog(Rhacophorus omeimontis)

Attendance patterns are a key factor affecting sexual selection and mating systems in lekbreeding species.However,there are few systematic studies on attendance patterns in lek-breeding anurans.In this study,we monitored a population of Omei treefrogs(Rhacophorus omeimontis) for four consecutive years to reveal in detail the effects of attendance patterns on mating systems.We found that(1) female nightly attendance was affected by male nightly attendance,and operational sex ratios(determined by male and female nightly attendance) ultimately determined the extent of female polyandry;(2) males surviving more than one breeding season maintained high chorus attendance and mating success,suggesting that male chorus attendance is a good predictor of male genetic quality;(3) the distributions of male mating success were not significantly different from a Poisson distribution,indicating a random mating pattern;and male mating success was not related to body size(size-assortative mating was not evident) but was significantly correlated with chorus attendance.Since the chorus attendance is a predictor of male genetic quality,females performing random mating were more likely to mate with more frequently present males and could therefore gain indirect benefits from mating with higher-than-average quality males,thereby producing good offspring without incurring the significant costs involved in prolonged searching for,and assessing males.Our systematic survey on the relationship between attendance patterns and the lek mating system in R.omeimontis could help us better understand in-depth anuran lek mating systems.

The genetic diversity, individual relatedness and possible mating system of an isolated population of the Cyprinid species Megalobrama pellgrini in upper reaches of the Changjiang (Yangtze) River, China

Megalobrama pellegrini is a cyprinid fish endemic to upper reaches of the Changjiang(Yangtze)River,China,which is also an important economic species in the local area.In recent years,resources of this species have decreased sharply and its conservation has drawn great attention.In the present study,we collected 120 individuals from the Longxi River,a tributary isolated from the main channel of the Changjiang River,where M.pellegrini is still relatively abundant.Using two different molecular markers,mitochondrial cytochrome b(cyt b)gene,and nuclear microsatellite(simple sequence repeat,SSR),we analyzed the genetic diversity of this isolated population.The results show that sequence genetic diversity was low(Hd:0.290 and P i:0.000 77 for cyt b gene),while the SSR genetic diversity was high(Ho:0.824 4±0.147 2,He:0.823 5±0.145 1).Analysis indicated that this population had experienced a bottleneck,with inbreeding and small effective population size(around 50).Based on SSR data,relatedness analyzing revealed that the 120 samples were grouped into 10 completely independent clusters.It was inferred that the mating system of M.pellegrini was polygamy.We suggested that the low genetic diversity could be induced by the overfishing and inbreeding depression.Therefore,we suggested that the urgent conservation measures should be taken to control the overfi shing and give better conditions for the fish to grow and spawn,then to restore population size.

Sexual dichromatism and assortative mating by multiple plumage color traits in wild Chestnut Thrush

Sex differences in plumage color are common in bird species.Some bird species are regarded as sexually monochromatic in human visual systems,and in recent years,some species are found to be of cryptic(to human)sexual dichromatism by spectrophotometric techniques.However,the functions of plumage color are still less understood in these species.Here,we focused on plumage color traits in the Chestnut Thrush(Turdus rubrocanus),which is considered as a sexually monochromatic bird by human observers.We used spectrometer analyses and avian visual modeling to investigate the color traits of males and females,and whether these color traits are involved in assortative mating.We found that Chestnut Thrush showed sexual dichromatism in bill,throat and wing,and pairs mated assortatively with colorations of throat,chest,crown and wing.We also found that color of tarsus was different between two consecutive years.These results revealed that Chestnut Thrush is sexually dichromatic in the avian visual system,and plumage color traits play important roles in mate choice.

Mating Ethogram of a Video-aided Study of Mating and Parturition in Captive Chinese Crocodile Lizards (Shinisaurus crocodilurus)

Mating behavior and parturition are important components in the life history of any species. The endangered Chinese crocodile lizard(Shinisaurus crocodilurus) is suffering dramatic population decreases in the wild. Successful captive breeding can provide individuals to be reintroduced into their natural habitat and help to restore the wild populations. Studying the mating behavior and parturition of these lizards in captivity will enable us understand how is this ancient species reproduction and optimize artificial reproduction protocol. We studied the mating behavior and parturition of Chinese crocodile lizards in captivity using video recordings at the Daguishan National Nature Reserve, China, from 2015 to 2017. We analyzed pre-copulation and copulation, which occurred in mid-March to late May from all studied years. Pre-copulation and copulation lasted on average 7.51(n=11) and 27.45(n=11) minutes, respectively. We found that large-bodied male lizards have longer copulation periods, a pattern seen in other lizard species. In the mating event, males always initiated sex, while the females were passive. The duration of parturition lasted 153.8 ± 26.8(n=46) minutes, and larger females had heavier clutches. In addition, even though Chinese crocodile lizards represent an ancient lizard clade with primitive characteristics, they still abide by the reproduction patterns seen in most other lizard species.

AN OBSERVATION STUDY ON BIOLOGICAL CHARACTERS AND MATING BEHAVIOR OF DAHURIAN CASEBEARER(COLEOPHORA DAHURICA FLKV.)ADULTS

Through rearing tests and observations under laboratory conditions,biologicalcharacters and mating behavior of Dahurian casebearer(Coleophora dahurica Flkv.)adultswere studied in this paper.Results discovered that the time of emergense of male adultswas 24h to 36h earlier than that of female adults.The peak of sex pheromone secretion ofthe female adults appeared of 24h to 42h after the emergence.The reaction of male adultson the sex pheromone was most sensitive during 30h to 48h after emerged,so the earlieremergence of the male adults was favorable to mating.The phenomenon of repeatedmating did not exist in female adults,but the male adults could mate for several times,with maximum of 4 times.There was a definite behavioral reaction during the matingperiod of male and female adults,and the certain period of feeding and mating times couldaffect the adults longervity to a certain degree.

Mating system and progeny genetic diversity of Camellia oleifera ‘Ruan Zhi’

Camellia oleifera Abel.is an important economic tree species of southern China.In this study,we evaluated the mating system and genetic diversity of a series of cultivars of C.oleifera‘Ruan Zhi’.A total of 159 individuals from the progenies of four cultivars were tested by simple sequence repeat molecular markers.Results reveal that 11 pairs of primers showed polymorphism and their polymorphism information content value was greater than 0.73,suggesting that these primers could be used to identify the genetic diversity of open-pollinated populations.The average number of effective alleles(Ne=4.88)was significantly different from the average number of alleles(Na=12.18),and their distribution in the sample population was not uniform.The average observed heterozygosity(Ho=0.96)was greater than the average expected heterozygosity(He=0.79),and the population heterozygote was excessive.Shannon index was 1.84 and populations showed high genetic diversity.As regards to the mating system,the multilocus outcrossing rate was 0.996,and the single locus 0.866.These results indicate a high degree of outcrossing by C.oleifera‘Ruan Zhi’.We recommend selecting individuals for high genetic gain from the progenies of cultivars because of outcrossing characteristics and genetic diversity for application to germplasm conservation and promotion.

No Evidence for Significant Effect of Body Size and Age on Male Mating Success in the Spot-legged Treefrog

In anurans, body size and age of individuals generally affect male mating success. To test whether body size and age have effects on male mating success in the foam-nesting treefrog Polypedates megacephalus, a species widely distributed in China, we analyzed differences in body size and age between mated and unmated males for three populations using a Generalized Linear Mixed Model(GLMM). The results showed that mated males did not exhibit larger body size and older age than unmated males, suggesting that large and/or old male individuals did not have greater mating success than small and/or young males. Moreover, we also found a non-significant size-assortative mating pattern for all populations. Our findings suggest that body size and age of the foam-nesting treefrog do not affect male mating success.

Behavior of Brown Bears (Ursus arctos) in Captivity during Mating Season

From 1991 to 1992, we observed behavior of 7 brown bears (5 females, 2 males) in mating season. Re-Sults showed tkat the oertrus of brown bears was mainly from May to July. The oeStrus ofmost individuals occwred at theend of May and the beginning of June. There were some differences in the oestrus among individuals. Average duration ofthe oestrus 30.8 days (16-50 days). The mating behavior was mainly observed during 8.00-9.00 a.m., and 15.00-16.00p.m.. Rest and sleep were the next behavior after mating for most bears, especially for male bears. All bears had poor appe-the. The Pattern and process of a successful mating was that a male bear approached a female, smelled the pudendum of thefemale, climbed on female hip, mated, parted and rested. Oestrus females approached males sometimes.

The Effects of Space Dimension and Temperature on the Cross Mating of Three Cryptic Species of the Bemisia tabaci Complex in China

The sweetpotato whitefly Bemisia tabaci(Homoptera:Aleyrodidae)is a destructive pest of agriculture and horticulture worldwide.Recent phylogenetic analysis using mitochondrial cytochrome oxidase 1 sequences indicates that this whitefly is a species complex including at least 24 morphologically indistinguishable but genetically distinct cryptic species.In this study,the inter-species crosses of Middle East-Asia Minor 1(MEAM1),Mediterranean(MED)and Asia II 7 cryptic species,which were referred to as B,Q and Cv biotypes before,were conducted in two different devices,leaf cages(7 cm3)and cylinder cages(280 cm3),and at three temperatures of 22,30 and 38°C.Results indicated that no female progeny were produced in the reciprocal cross between MEAM1×Asia II 7,between MED×Asia II 7 cryptic species neither in leaf cage nor in cylinder cages,while 0.81 and 1.37% of females in the offspring were recorded in the reciprocal cross between MEAM1×MED in leaf cage experiments.Approximately 0.95-0.98% female progeny were recorded in the reciprocal cross between MEAM1×MED at 30°C,0.77% female progeny were recorded in the single cross direction between MEAM1 × MED at 22°C,and no female progeny were found in their reciprocal cross at 38°C in leaf cage.Our findings indicated that neither space dimension nor temperature have a significant effect on the hybridization of different B.tabaci cryptic species.

Population structure and mating system of the Red-crested Korhaan(Lophotis ruficrista) in South Africa

Background: The mating system of the korhaans and bustards in southern Africa is either based on polygyny or monogamy. The Red-crested Korhaan(Lophotis ruficrista) has been described as polygynous but otherwise very little is known about its breeding biology. The aims were to describe the population structure and male behavior during breeding.Methods: The data collected for this paper was mainly based on field transect surveys carried out in 2009, 2010 and 2011. The population structure of the Red-crested Korhaan in the temperate Borakalalo Game Reserve(BGR)was compared with that in the arid Molopo Nature Reserve(MNR)(both situated in the North West province of South Africa). The study was mainly conducted in the BGR but additional work was conducted in the MNR for comparison.Results: The difference in mean group sizes between MNR(1.03) and BGR(1.07) was statistically not significant.Group sizes were not affected by climate despite the fact that the BGR received about 650 mm precipitation per annum and the MNR about 200 mm. In both reserves the apparent sex ratios were skewed in favor of males(1:0.29 in the BGR and 1:0.1 in the MNR). The population was dispersed in a clumped manner which is ascribed to the formation of leks. Leks were positioned in open habitat while females invariably concealed themselves under cover.Conclusions: The leks formed the pivot of the mating system of the Red-crested Korhaan and are identifiable social structures that field ecologists can use to monitor population stability.

Remating in Anastrepha sp.1 aff.fraterculus(Diptera:Tephritidae):An Analysis Using rose Mutation

The propensity of females to cross with more than one male is a relevant aspect in tephritid fruit fly biology since many species are pests of fruticulture.The knowledge about mating systems of a target pest-species is crucial for defining efficient strategies for insect population control,e.g.,for the sterile insect technique(SIT).The aim of this study was to evaluate the propensy to remate of the tephritid Anastrepha sp.1 aff.fraterculus females.For this purpose it was used an autosomic recessive mutation,rose,that affects eye-color,in two designed experimental systems:one in which wild-type and rose males were sequentially offered to cross with rose females and another one in which the rose females had to choose to cross with a wild-type,to a rose male or to both(remate).By simple analyses of the progeny phenotypes it was possible to recognize whether the females had remated or not.About a third of the females produced mixed progenies with wild-type and rose individuals,thereby indicating remating during the week the experiment lasted.Data indicated that remating rate was higher than previously reported for this species,and it could be shown that the sperms derived from the different males the females had crossed had been used in egg fertilization.

A CONSANGUINEOUS MATING COUPLE AND THEIR CONCOMITANT ESOTROPIA TWINS

A first cousin marriage couple and their 8-year-old identical twin daughters with concomitant strabismus are described.This family would indicate an autosomal recessive inheritance in concomitant strabismus.

Peak Mating and Breeding Period of the Humpback Whale —(Megaptera novaeangliae) in Okinawa Island, Japan

Although detailed knowledge on breeding ecology of humpback whales is required for developing effective and sustainable whale watching programs in breeding areas, the breeding ecology of this species is still poorly understood. Hence, we examine the migratory timing of humpback whales in Okinawa that is one of their breeding ground, distinguishing the reproductive status (male, female, or female with a calf), group compositions (singleton, pair, or whales more than three) and group types (singer or competitive group) in order to assess the peak period of breeding activities. A total of 1192 days of photo-identification surveys were conducted from 1991 to 2012 and a total of 7366 humpback whales were sighted during the surveys. Among them, 1284 whales were sex-determined (848 males, 147 females and 289 females with a calf), 1138 singletons, 1416 pairs and 710 groups of more than three whales were observed. Females without calves tended to occur from late January to late February, which was the beginning of the breeding season and male-female pairs were observed most frequently during this period. The peak occurrence of competitive group which was considered a mating-related behavior group, formed by females and males, was also observed during this period. These results indicated that humpback whales peak mating period in Okinawa occurred between late January and late February. Females with a calf tended to increase from mid-February toward the end of the breeding season maintaining a high sighting per unit effort (SPUE) value in late March. We, therefore, suggested that the peak time of birthing and newborn care was probably that period in Okinawa. These findings extended our knowledge on the reproductive ecology of humpback whales in Okinawan waters.

Intelligent Co-ordinate Control for Mating Process of Underwater Vehicle Based on TFPN

In order to reduce time and improve the probability of successful matting it is useful to co-ordinate between the movement control and mating process of the underwater vehicle. Because it is hard to control with the common method under the condition of mating process, the hierarchical intelligent control is introduced. Timed fuzzy Petri net (TFPN), which is the integration of PN and fuzzy reasoning, is used in the design of coordinate level of hierarchically intelligent control. It made the control process better in reflecting the characteristics of time-driven, event-driven, fuzzy information and so on. The test shows that TFPN could shorten the time of mating and enhance the efficiency.

Mating behavior and sex pheromone release rhythm of Holotrichia parallela(Coleoptera: Melolonthidae)

Mating behavior and sex pheromone release rhythm of Holotrichia parallela was studied in this research. The maximum mating times were 3 for female and 4 for male. Average mating times were 1.06 for female and 0.91 for male. L-isoleucine methyl ester(LIME), a major component of pheromone, increased gradually from 14:00 and peaked at 19:00, then dropped sharply at 20:00 and remained low at 24:00.(R)-(-)-linalool(referred as linalool below) maintained similar levels throughout the study period. Calling and mating activity significantly decreased LIME titer, but not linalool. Analyses of 11 samples collected during calling days(20 d-70 d) revealed that LIME production was affected by female age. LIME titers increased from 20 d to 45 d, and decreased from 45 d to 70 d. While linalool titers remained at similar levels at all sampling dates. The highest ratio between LIME and linalool was 12 and the lowest was 4. Field tests confirmed that the most attractive ratios of LIME: linalool in early season(June 1 to 20) and late season(August 1 to 20) were 6:1, while in the most serious injury stage(June 20 to August 1) was 12:1. This is the first report about circadian rhythmicity of sex pheromone in Holotrichia parallela, which provides a basis for controlling it in field.

Mating behaviors in ovoviviparous black rockfish(Sebastes schlegelii):molecular function of prostaglandin E2 as both a hormone and pheromone

Prostaglandins(PGs)are profound hormones in teleost sexual behavior,especially in mating.PGs act as pheromones that affect the olfactory sensory neurons of males,inducing the initiation of a series of mating behaviors.However,the molecular mechanism by which PGs trigger mating behavior in ovoviviparous teleosts is still unclear.In the present study,we employed the ovoviviparous black rockfish(Sebastes schlegelii),an economically important marine species whose reproductive production is limited by incomplete fertilization,as a model species.The results showed that when the dose of PGE2 was higher than 10 nmol/L,a significant(P<0.05)increase in mating behaviors was observed.Dual-fluorescence in situ hybridization indicated that PGE2 could fire specific neurons in different brain regions and receptor cells in the olfactory sac.After combining with specific neurons in the central nervous system(CNS),a series of genes related to reproduction are activated.The intracerebroventricular administration of PGE_(2) significantly increased lhb levels(P<0.05)in both sexes.Moreover,steroidogenesis in gonads was also affected,inducing an increase(P<0.05)in E_(2) levels in males and T levels in females.PGE_(2) levels were also increased significantly(P<0.05)in both sexes.The present study revealed that PGE2 can activate mating behavior in black rockfish in both hormone and pheromone pathways,leading to variations in sex steroid levels and activation of reproductive behaviors.Our results provide not only novel insight into the onset of mating behaviors in ovoviviparous teleosts but also solutions for the incomplete fertilization caused by natural mating in cage aquaculture.

Mismatch between calf paternity and observed copulations between male and female reindeer:Multiple mating in a polygynous ungulate?

In polygynous systems,such as that exhibited by reindeer Rangifer tarandus,mate choice can be difficult to disentangle from male intrasexual competition because male behavior may constrain female choice.Multiple mating may provide an avenue for female mate choice,though it is difficult to identify using behavioral estimators alone.Molecular techniques address this issue by affording ecologists an opportunity to reassess mating systems from a genetic perspective.We assessed the frequency and possible explanations for multiple mating in reindeer using a genetic approach to determine the success of observed copulations in a semi-domesticated herd in Kaamanen,Finland.Behavioral and genetic data were synthesized with population characteristics over a 7-year period to test the hypothesis that,if present,polyandry in reindeer is driven by sexual harassment from sub-dominant males.We observed multiple mating in 42%of females,with as many as 60%exhibiting multiple mating in certain years.We found no evidence that multiple mating resulted from sexual harassment by sub-dominant males,suggesting that it is likely a deliberate strategy among females.Conversion rate of copulations into paternities varied with male size,with smaller males more likely to experience mismatch than larger males.Female preference for larger males persisted despite the occurrence of multiple mating,possibly suggesting a mechanism for cryptic post-copulatory selection.We suggest further research to delineate the possible influence of cryptic post-copulatory selection and multiple mating to defend against infertility in exhausted males.

Atmospheric humidity regulates same-sex mating in Candida albicans through the trehalose and osmotic signaling pathways

Sexual reproduction is prevalent in eukaryotic organisms and plays a critical role in the evolution of new traits and in the generation of genetic diversity.Environmental factors often have a direct impact on the occurrence and frequency of sexual reproduction in fungi.The regulatory effects of atmospheric relative humidity(RH)on sexual reproduction and pathogenesis in plant fungal pathogens and in soil fungi have been extensively investigated.However,the knowledge of how RH regulates the lifecycles of human fungal pathogens is limited.In this study,we report that low atmospheric RH promotes the development of mating projections and same-sex(homothallic)mating in the human fungal pathogen Candida albicans.Low RH causes water loss in C.albicans cells,which results in osmotic stress and the generation of intracellular reactive oxygen species(ROS)and trehalose.The water transporting aquaporin Aqy1,and the G-protein coupled receptor Gpr1 function as cell surface sensors of changes in atmospheric humidity.Perturbation of the trehalose metabolic pathway by inactivating trehalose synthase or trehalase promotes same-sex mating in C.albicans by increasing osmotic or ROS stresses,respectively.Intracellular trehalose and ROS signal the Hog1-osmotic and Hsf1-Hsp90 signaling pathways to regulate the mating response.We,therefore,propose that the cell surface sensors Aqy1 and Gpr1,intracellular trehalose and ROS,and the Hog1-osmotic and Hsf1-Hsp90 signaling pathways function coordinately to regulate sexual mating in response to low atmospheric RH conditions in C.albicans.