Detection of mRNA Expression and Copy Number Variations Within the Goat FecB Gene Associated With Litter Size

Abstract

The Booroola fecundity (FecB) gene, as the first major fecundity gene identified in Booroola sheep, has attracted careful attention. So far, previous research have uncovered the FecB mutation (Q249R) as the main mutation by virtue of which sheep exhibits multiple lambing phenomena. This mutation is now being intensively studied and widely used. However, such effect of the FecB mutation has not been applied to goats, and similar types of the FecB gene in goats still need to be studied. Thus, the current study attempted to verify potential mutations in the goat FecB gene as well as investigate their functions related to fecundity. First, FecB expression was investigated in six different goat tissues, and we found that FecB expression was highest in the mammary gland, followed by the ovary. Next, the influence of the FecB gene was analyzed from a new perspective, where five potential copy number variations (CNVs) (CNV1–5) within the FecB gene were identified for the first time, and then their effects on litter size were measured. Our results point out that CNV3 (P = 3.44E-4) and CNV5 (P = 0.034) could significantly influence the litter size of goats. Identically, the combination genotype of CNV3 and CNV5 which consisted of their dominant genotypes was also significantly associated with goat litter size (P = 7.80E-5). Hence, CNV3 and CNV5 could serve as potential DNA molecular markers applied to DNA editing and DNA microarray. Additionally, the abovementioned study has laid a theoretical foundation for the detection of potential fertility-related quantitative trait loci within the goat FecB gene.

Are Copy Number Variations within the FecB Gene Significantly Associated with Morphometric Traits in Goats?

“…In our previous study, five CNVs within Fec B were significantly associated with goat litter sizes [ 16 ]. Given that litter size is positively associated with morphometric traits [ 27 ], association analyses between these CNVs and morphometric traits were conducted in SBWC, GZHM, and Nubian goats.…”

“…Moreover, differences in breed and sample size may also have contributed to this finding. In our previous study, we identified five CNVs within the Fec B gene in SBWC goats and established that CNV3 and CNV5 were significantly associated with litter size [ 16 ]. Since there is a positive association between litter size and morphometric traits, we hypothesized that the Fec B gene also influences growth performance in goats [ 20 ].…”

“…Based on the resequencing data from the goat pan-genome database ( (accessed on 7 March 2022)) and CNVcaller, a read-depth method was used to identify and genotype the CNVs within the goat Fec B gene. All primers used in this study were described in our previous study [ 16 ] ( Supplementary Table S1 ). The CNVs were genotyped using a quantitative PCR (qPCR) technique.…”

“…Recently, this issue has received increasing attention, and several studies have revealed fertility-related mutations in goats [ 14 , 15 ]. For example, five copy number variations (CNVs) within the Fec B gene were detected in Shaanbei white cashmere (SBWC) goats, two of which significantly influenced litter size [ 16 ]. Moreover, two novel single nucleotide polymorphisms (SNPs) (A775G and G777A) were confirmed in Markhoz goats; however, this requires further investigation [ 17 ].…”

Goat SNX29: mRNA expression, InDel and CNV detection, and their associations with litter size

“…Previously explored experimental procedures were as follows, 95°C for 45 s, 40 cycles of 15 s at 95°C and 45 s at 60°C. Finally, the result was processed by method 2*2 −Δ Ct ·2*2 −Δ Ct >2 was Gain, it < 2 was Loss, it = 2 was Median genotype ( 29 ).…”