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Kisspeptin (Kp), an upstream regulator of GnRH release, is essential for the development and function of reproductive axis. Previously, we demonstrated the localization of Kp and its receptor (Kiss1r) in the active follicle in the bubaline ovary. Present study aimed to determine the effect of Kp on granulosa cell (GCs) functions, especially oestradiol (E2) and progesterone (P4) production, and differential expression of genes regulating the proliferation, apoptosis and steroidogenesis in the buffalo. The ovaries with 6–10 mm size follicles obtained from the cyclic buffaloes after slaughtering were used for isolation of GCs for in vitro study. The primary GCs culture was treated with Kp (0, 10, 50 and 100 nM) and incubated for 48 h. Production of E2 and P4 was estimated in the culture supernatant by ELISA. The expression of gonadotropin receptors (FSHR and LHR), steroidogenic genes (STAR, 3β‐HSD, CYP19A1), proliferation marker (PCNA), apoptotic factors (CASP3 and BCL2) and Kp signalling molecule (extracellular signal‐regulated kinase 1/2, ERK1/2 and p‐ERK1/2) was studied in the GCs by qPCR. Significant E2 production was found in the Kp 50 and 100 nM groups (p <.05), whereas P4 production was reduced in Kp 100 nM group (p <.05). There was concomitant upregulation of FSHR, ERK1/2, STAR and CYP19A1 in the Kp 100 nM treated GCs. In addition, Kp at 100 nM stimulated the proliferation of GCs by upregulating the expression of BCL2 (5.0 fold) and PCNA (94.9 fold). Further, high immunoreactivity of p‐ERK1/2 was observed in the Kp‐treated GCs. It was concluded that Kp at 100 nM concentration stimulated E2 production by upregulating the steroidogenic pathway through ERK1/2, STAR and CYP19A1 and modulating PCNA and BCL2 expressions in the GCs. Further experiments are warranted using Kp antagonist in different combinations to establish the signalling pathway in Kp‐mediated steroidogenesis in the GCs for developing strategies to control ovarian functions. [ABSTRACT FROM AUTHOR]

Sexed semen facilitates additional female calf production for the expansion of a herd at a faster rate and also curtails the surplus production of unwanted male calves. A study was conducted to evaluate the performance of sexed semen in indigenous Tharparkar cows based on 114 artificial inseminations (AI) performed at natural oestrus using two protocols i.e., single AI (n = 48) and double AI (n = 66). Overall, the first service conception rate (CR) was significantly higher in double (53.0%) than single (33.3%) AI protocol. The odds ratio of conception rate in double AI was 2.26 (χ2 = 4.4, df = 1, p =.04) with respect to single AI. The time that elapsed since the detection of oestrus to insemination was also analysed. In a single AI protocol, the CR was higher (p <.05) at 16 h (54.6%) than insemination at 8 h (27.0%) following the onset of oestrus. Yet, the CR using double AI protocol did not differ (p =.73) significantly when AIs were performed either at 8 h and 24 h (51.9%) or 16 h and 24 h (57.1%) post onset of oestrus. Besides, like the single AI protocol, the parity of the animals also influenced the CR, being higher in heifers (n = 22) than those of parous (n = 92) cows (72.73 vs. 40.43%, χ2 = 7.48, df = 1, p =.006) in the present study. The odds ratio of conception in heifers was 3.93 with respect to parous cows. Overall, the birth of female calf was 91.7%. In conclusion, the present study indicates a future promise of the sexed semen for the production of more female offspring from Tharparkar cattle. [ABSTRACT FROM AUTHOR]

Determination of factors affecting sex ratio is important while considering application of sex ratio enrichment approach. Present study aimed to design a SYBR Green qPCR‐based method for measurement of primary sex ratio and to evaluate different factors (genetic group, sire, spermiogenic cycle and processing layer) affecting boar sperm sex ratio. The qPCR was based on relative copy number analysis of sex chromosome‐specific single copy gene fragments with an autosomal gene as reference and was evaluated using DNA dilution series from pigs with numerically normal karyotype. The sex ratio was estimated from genomic DNA samples isolated from boar semen collected from different genetic groups at different time points and different processing layers. The X chromosome frequencies of semen samples revealed significant effect of genetic group. However, significant variation was observed neither within same genetic group nor between ejaculates of different spermatogenic cycles. Among the processing techniques studied, swim‐up technique produced a significant X sperm enrichment in comparison to control whereas, Percoll density gradient failed to show any significant difference among layers. The lower layer in swim‐up technique was found to contain higher proportion of X sperms. The designed qPCR is found to be an easy, less time‐consuming method and does not require high end laboratory facilities or the specialized expertise. The lower layer of swim‐up processing has a scope for X sperm enrichment in boar semen with proper validation. [ABSTRACT FROM AUTHOR]

The improvement in imputation accuracy diminished across different methods of selecting SNPs with increased panel density. 5 O'Brien, A.C., Judge, M.M., Fair, S. & Berry, D.P. (2019) High imputation accuracy from informative low-to-medium density single nucleotide polymorphism genotypes is achievable in sheep1. Genomic technologies have not penetrated enough in livestock, especially in developing nations where animals from a particular breed/population cannot be concurrently genotyped mainly due to financial constraints. [Extracted from the article]