Whole‑genome transcriptome and DNA methylation dynamics of pre‑implantation embryos reveal progression of embryonic genome activation in buffaloes

Background During mammalian pre-implantation embryonic development(PED),the process of maternal-to-zygote transition(MZT)is well orchestrated by epigenetic modification and gene sequential expression,and it is related to the embryonic genome activation(EGA).During MZT,the embryos are sensitive to the environment and easy to arrest at this stage in vitro.However,the timing and regulation mechanism of EGA in buffaloes remain obscure.Results Buffalo pre-implantation embryos were subjected to trace cell based RNA-seq and whole-genome bisulfite sequencing(WGBS)to draw landscapes of transcription and DNA-methylation.Four typical developmental steps were classified during buffalo PED.Buffalo major EGA was identified at the 16-cell stage by the comprehensive analy-sis of gene expression and DNA methylation dynamics.By weighted gene co-expression network analysis,stage-spe-cific modules were identified during buffalo maternal-to-zygotic transition,and key signaling pathways and biological process events were further revealed.Programmed and continuous activation of these pathways was necessary for success of buffalo EGA.In addition,the hub gene,CDK1,was identified to play a critical role in buffalo EGA.Conclusions Our study provides a landscape of transcription and DNA methylation in buffalo PED and reveals deeply the molecular mechanism of the buffalo EGA and genetic programming during buffalo MZT.It will lay a foundation for improving the in vitro development of buffalo embryos.

Application Status,Problems and Countermeasures of Dairy Herd Improvement( DHI) in Dairy Buffalo Industry

The development of buffalo milk industry in China encounters the problems of small high yield populations and insufficient excellent provenance. There- fore, it is necessary to carry out dairy herd improvement （DHI） to increase dairy buffalo herd productivity. This paper reviewed the situation and problems of DHI in dairy buffalo, and the corresponding opinions and suggestions were put forward.

Endocrine and ovarian responses in water buffalo cows immunized against inhibin and subjected to the Ovsynch protocol

The aim of this study was to investigate the feasibility of stimulating ovarian fol icle development in order to improve fertility in water buffalo cows by immunization against inhibin. The experiment was carried out in early summer (May) and included 24 multi-parity crossbred Murrah-Swamp buffaloes that were divided into immunized (n=11) and control (n=13) groups. Each immunized cow was administered with a 2-mL immunogen of mineral oil adjuvant containing 2 mg of recombinant inhibinα-subunit fusion protein. The controls were treated with the adjuvant only. Al animals received Ovsynch protocol treatment, starting on the day of the antigen administration, and they were artiifcial y inseminated upon behavioral estrus. As a result, al of the immunized buffaloes generated antibodies against inhibin during the experimental period and had higher plasma concentrations of fol icle-stimulating hormone (FSH), activin, and estradiol (E2) related to estrous expression. A higher proportion of immunized animals expressed estrus behavior than did the controls (72%vs. 30%, P<0.05). On aver-age, inhibin-immunized buffaloes had signiifcantly more large fol icles (≥9 mm in diameter) than the controls (mean±SEM;1.2±0.1 vs. 0.84±0.1, respectively;P<0.05) and a slightly higher mean total number of fol icles (≥2 mm;11.4±0.7 vs. 9.0±1.1, respectively;P=0.09) and smal (2–4 mm) fol icles (8.81±0.6 vs. 6.84±1.0, respectively;P=0.12). A higher percentage of cows ovulated in the immunized group than in the control group (91%(10/11) vs. 54%(7/13), respectively;P<0.05). Moreover, inhibin-immunized cows had slightly larger corpus luteum (CL) than the controls 9 days after ovulation and signiifcantly higher (P<0.01) post-ovulation peak plasma progesterone (P4) concentrations. Immunization against inhibin also mar-ginal y increased the conception rate 42 days after insemination (45.8%vs. 15.4%;P>0.05). These results demonstrate that immunization against inhibin, coupled with the treatment with the Ovsynch protocol, can constitute a new technique to increase fertility in water buffalo cows.

Prospects of HSP70 as a genetic marker for thermo-tolerance and immuno-modulation in animals under climate change scenario

Heat stress induced by long periods of high ambient temperature decreases animal productivity,leading to heavy economic losses.This devastating situation for livestock production is even becoming worse under the present climate change scenario.Strategies focused to breed animals with better thermotolerance and climatic resilience are keenly sought these days to mitigate impacts of heat stress especially in high input livestock production systems.The 70-kDa heat shock proteins(HSP70) are a protein family known for its potential role in thermo-tolerance and widely considered as cellular thermometers.HSP70 function as molecular chaperons and have major roles in cellular thermotolerance,apoptosis,immune-modulation and heat stress.Expression of HSP70 is controlled by various factors such as,intracellular pH,cyclic adenosine monophosphate(cyclic AMP),protein kinase C and intracellular free calcium,etc.Over expression of HSP70 has been observed under oxidative stress leading to scavenging of mitochondrial reactive oxygen species and protection of pulmonary endothelial barrier against bacterial toxins.Polymorphisms in flanking and promoter regions in HSP70 gene have shown association with heat tolerance,weaning weight,milk production,fertility and disease susceptibility in livestock.This review provides insight into pivotal roles of HSP70 which make it an ideal candidate genetic marker for selection of animals with better climate resilience,immune response and superior performance.

Gut microbiome colonization and development in neonatal ruminants: Strategies, prospects, and opportunities

Colonization and development of the gut microbiome is a crucial consideration for optimizing the health and performance of livestock animals. This is mainly attributed to the fact that dietary and management practices greatly influence the gut microbiota, subsequently leading to changes in nutrient utilization and immune response. A favorable microbiome can be implanted through dietary or management in-terventions of livestock animals, especially during early life. In this review, we explore all the possible factors (for example gestation, colostrum, and milk feeding, drinking water, starter feed, inoculation from healthy animals, prebiotics/probiotics, weaning time, essential oil and transgenesis), which can influence rumen microbiome colonization and development. We discuss the advantages and disadvantages of potential strategies used to manipulate gut development and microbial colonization to improve the production and health of newborn calves at an early age when they are most susceptible to enteric disease. Moreover, we provide insights into possible interventions and their potential effects on rumen development and microbiota establishment. Prospects of latest techniques like transgenesis and host genetics have also been discussed regarding their potential role in modulation of rumen microbiome and subsequent effects on gut development and performance in neonatal ruminants.