Feed restriction regime in a rabbit line selected for growth rate alters oocyte maturation manifested by alteration in MSY2 gene expression

Abstract

Young rabbit females selected for growth rate may have nutritional needs, which may not be met with the common practice of feed restriction during rearing in commercial rabbit production. The aim of this study was to analyse whether two different feeding programmes: ad libitum or restricted (130 g/day) feeding, applied in young rabbit females for 1 month at the end of rearing, could modulate the origin of ovulation process and the quality of the oocytes. At 16 weeks of age, 34 females were randomly assigned to restricted or ad libitum feeding, maintaining these conditions for a month. Then, in an initial experiment, transcriptional profiling of hypothalamus-hypophysis tissue was performed to assess failure to ovulate. In the second experiment, the gene expression analysis of some candidate genes related to oocytes quality was performed. Our results demonstrated that neither of the two feeding programmes modified the transcription of hypothalamus-hypophysis tissue, while the only differences in MSYR expression were found in in vivo mature oocytes ready for successful fertilization. Specifically, MSYR was over-expressed in oocytes from females fed ad libitum. MSYR is one of the most abundant proteins in the oocyte and has proven to be a key regulator of maternal RNA transcription and translation. This finding suggests that MSYR gene is a promising gene in our understanding of the relationship between high growth rate and reproductive performance decline.

CircRNA expression in chicken granulosa cells illuminated with red light

“…Furthermore, PIK3R1 is also involved in signaling pathways that control GC proliferation and oocyte maturation ( Zheng et al, 2012 ). EGFLAM is involved in cellular growth, differentiation, and proliferation ( Naturil-Alfonso et al, 2017 ), but Vicente et al (2013) found that expression of EGFLAM is negatively correlated with foetal growth. Herein, expression of EGFLAM levels was lower in the RL group, demonstrating a negative correlation with follicle maturation.…”

CircRNA Expression in Chicken Granulosa Cells Illuminated with Red Light

“…PIK3R1 plays an important role in regulating ovarian activities in yak seasonal reproduction [45]. EGFLAM is involved in cellular growth, differentiation and proliferation, including angiogenesis and membrane fusion [46]. Competing endogenous RNAs (ceRNAs) analysis revealed that circRNAs can compete with miRNAs to alter the expression of key genes involved in GC differentiation and follicle development.…”

Challenges in rabbit doe feeding, including the young doe

“…Similarly, in a rabbit line selected for growth rate, Naturil- Alfonso et al (2016) observed worse reproductive performance results (-0.2 kindling rate, +0.18 and +0.29 gestational and foetal losses and -1.6 kits during the first three reproductive cycles) when rabbit does were restricted (130 g/d) for a month before being mated. However, in other studies done with the same scheme and line, the differences in reproductive performance disappeared (Naturil-Alfonso et al, 2017). In maternal crossbreed females, Martińez-Paredes et al (2012) observed that a restriction of 140 g/d from 12 wk of age, with a flushing 4 d before mating (18 wk of age), led young rabbit does to show an energy intake below to the recommendations (Xiccato and Trocino, 2010), causing a delay in body development compared to those fed ad libitum.…”