TLR7/8 signalling affects X-sperm motility via the GSK3α/β-hexokinase pathway for the efficient production of sexed dairy goat embryos

Background:Goat milk is very similar to human milk in terms of its abundant nutrients and ease of digestion.To derive greater economic benefit,farmers require more female offspring(does);however,the buck-to-doe offspring sex ratio is approximately 50%.At present,artificial insemination after the separation of X/Y sperm using flow cytometry is the primary means of controlling the sex of livestock offspring.However,flow cytometry has not been successfully utilised for the separation of X/Y sperm aimed at sexing control in dairy goats.Results:In this study,a novel,simple goat sperm sexing technology that activates the toll-like receptor 7/8(TLR7/8),thereby inhibiting X-sperm motility,was investigated.Our results showed that the TLR7/8 coding goat Xchromosome was expressed in approximately 50%of round spermatids in the testis and sperm,as measured from cross-sections of the epididymis and ejaculate,respectively.Importantly,TLR7/8 was located at the tail of the Xsperm.Upon TLR7/8 activation,phosphorylated forms of glycogen synthase kinaseα/β(GSK3α/β)and nuclear factor kappa-B(NF-κB)were detected in the X-sperm,causing reduced mitochondrial activity,ATP levels,and sperm motility.High-motility Y-sperm segregated to the upper layer and the low-motility X-sperm,to the lower layer.Following in vitro fertilisation using the TLR7/8-activated sperm from the lower layer,80.52±6.75%of the embryos were XX females.The TLR7/8-activated sperm were subsequently used for in vivo embryo production via the superovulatory response;nine embryos were collected from the uterus of two does that conceived.Eight of these were XX embryos,and one was an XY embryo.Conclusions:Our study reveals a novel TLR7/8 signalling mechanism that affects X-sperm motility via the GSK3α/β-hexokinase pathway;this technique could be used to facilitate the efficient production of sexed dairy goat embryos.

Sex determination mechanisms and sex control approaches in aquaculture animals

Aquaculture is one of the most efficient modes of animal protein production and plays an important role in global food security.Aquaculture animals exhibit extraordinarily diverse sexual phenotypes and underlying mechanisms,providing an ideal system to perform sex determination research,one of the important areas in life science.Moreover,sex is also one of the most valuable traits because sexual dimorphism in growth,size,and other economic characteristics commonly exist in aquaculture animals.Here,we synthesize current knowledge of sex determination mechanisms,sex chromosome evolution,reproduction strategies,and sexual dimorphism,and also review several approaches for sex control in aquaculture animals,including artificial gynogenesis,application of sex-specific or sex chromosome-linked markers,artificial sex reversal,as well as gene editing.We anticipate that better understanding of sex determination mechanisms and innovation of sex control approaches will facilitate sustainable development of aquaculture.

Progress in studies of sex determination mechanisms and sex control techniques in Cynoglossus semilaevis(half-smooth tongue sole)

The Cynoglossus semilaevis(half-smooth tongue sole) is a marine flatfish of great commercial value for fisheries and aquaculture in China.It has a female heterogametic sex determination system(ZW/ZZ) and environmental factors can induce sex-reversal of females to phenotypic males,suggesting that it is a promising model for the study of sex determination mechanisms.Additionally,females grow much faster than males and it is feasible to improve the aquaculture production through sex control techniques.This paper reviews the progress in research on sex determination mechanisms research in our laboratory.We have completed whole-genome sequencing and revealed the genome organization and sex chromosome evolution of C.semilaevis.A putative male determining gene dmrt1 was identified and DNA methylation was verified as having a crucial role in the sex reversal process.Genetic maps and sex-specific biomarkers have been used in a marker-assisted selection breeding program and for differentiation of the fish sex.Development and improvement of sex control technologies,including artificial gynogenesis and production of breeding fry with high proportion of females,is also reviewed.These research advances have provided insight into the regulation of sex determination and enabled efficient sex management in artificial culturing of C.semilaevis.

If Mom OKs Birth Control,Teen Sex More Likely

美国的科技领先世界一步,而该国的unwed mothers的人数恐怕也为世界之最。所谓unwed mothers指未婚先孕者,多系十多岁的学生娃。 国人视“未婚先孕”为见不得人之事,这是我们的文化。而美国的unwedmothers却少有羞耻感,她们落落大方,将自己的孩子带到学校里来,同学围观,就如同围观已婚夫妇所生的小孩一样,根本谈不上是什么social stigma(社会的耻辱)！ 本文提出了一个非常重要的问题:父母是否应该向其十多岁的子女公开自己避孕的措施?父母是否应该和他们谈“性”?本文在对万名学生调研的基础上对此问题作出了辨证回答: 1/这种“公开”和“谈论”,会令子女more likely to become sexually active,或者twice as likely to lose their virginity(处女性)。 2/这种“公开”和“谈论”利大于弊。因为其子女将less likely to have sex overthe study period.And when they did have sex,these kids were more likely to usebirth control and less likely to become pregnant. 我国青少年的性知识从哪里获得?笔者没有读到过这方面的调查,“无师自通”者也许不乏其人。为人父母者是否应该和自己的子女谈性论爱,这也许不是一个简单的“应该/不应该”的问题。真正在起作用的还有我们的文化传统。

Rethinking fish biology and biotechnologies in the challenge era for burgeoning genome resources and strengthening food security

Fish biology has been developed for more than 100 years,but some important breakthroughs have been made in the last decade.Early studies commonly concentrated on morphology,phylogenetics,development,growth,reproduction manipulation,and disease control.Recent studies have mostly focused on genetics,molecular biology,genomics,and genome biotechnologies,which have provided a solid foundation for enhancing aquaculture to ensure food security and improving aquatic environments to sustain ecosystem health.Here,we review research advances in five major areas:(1)biological innovations and genomic evolution of four significant fish lineages including non-teleost ray-finned fishes,northern hemisphere sticklebacks,East African cichlid fishes,and East Asian cyprinid fishes;(2)evolutionary fates and consequences of natural polyploid fishes;(3)biological consequences of fish domestication and selection;(4)development and innovation of fish breeding biotechnologies;and(5)applicable approaches and potential of fish genetic breeding biotechnologies.Moreover,five precision breeding biotechniques are examined and discussed in detail including gene editing for the introgression or removal of beneficial or detrimental alleles,use of sex-specific markers for the production of mono-sex populations,controllable primordial germ cell on-off strategy for producing sterile offspring,surrogate broodstock-based strategies to accelerate breeding,and genome incorporation and sexual reproduction regainbased approach to create synthetic polyploids.Based on these scientific and technological advances,we propose a blueprint for genetic improvement and new breed creation for aquaculture species and analyze the potential of these new breeding strategies for improving aquaculture seed industry and strengthening food security.