SummaryA meta‐analysis on the effects of A and B alleles, the most frequent alleles of CSN3 gene, on milk yield and composition traits was conducted by pooling a large dataset consisting of 30 471 genotyped cattle. Four genetic models, comprising dominant (AA + AB vs. BB), recessive (AA vs. AB + BB), additive (AA vs. BB) and co‐dominant (AA + BB vs. AB), were employed to analyze data. Standardized mean difference (SMD) was used to measure the size of the effects of A and B alleles of CSN3 on studied traits. Effect sizes of 0.2, 0.5 and 0.8 represent small, medium and large effects, respectively. The results indicate that B allele, in the form of BB genotype, has a significant, but medium effect on lactation yield under dominant (SMD = 0.259, P‐value = 0.006) and additive (SMD = 0.279, P‐value = 0.035) models. Moreover, a small decrease in the fat percentage occurred in cows having A allele under dominant (SMD = −0.077, P‐value = 0.006) and additive (SMD = −0.106, P‐value = 0.035) models. Furthermore, CSN3 variants significantly but slightly affect protein percentage under dominant (SMD = −0.146, P‐value = 0.000), recessive (SMD = −0.077, P‐value = 0.000) and additive (SMD = −0.219, P‐value = 0.000) models, showing the negative effect of A allele on this trait. Meta‐analysis results reveal that daily milk yield is slightly affected by CSN3 variants under recessive (SMD = 0.056, P‐value = 0.033) and additive (SMD = 0.061, P‐value = 0.013) genetic models. There is no effect of CSN3 variants on either protein or fat yield. In addition, the effects of CSN3 variants on milk‐related traits were not observed under the co‐dominant model. Sensitivity and publication bias analyses were carried out to confirm the stability of meta‐analyses results.
Abstract. Litter size is an important economic trait in the goat industry. Previous studies on the bone morphogenetic protein 15 (BMP15) gene detected some single-nucleotide polymorphisms (SNPs) such as c.963A>G that were associated with an increase in ovulation rate and litter size. The aim of this study was to conduct a meta-analysis on the effect of this polymorphism on litter size. We gathered and pooled data from five eligible published studies. To investigate the effect of c.963A>G on litter size, we utilized four different genetic models assuming dominant (GG + GA vs. AA), recessive (GG vs. GA + AA), additive (GG vs. AA) and co-dominant (GG + AA vs. GA) model of inheritance. Data were analyzed under random-effects models based on the I2 value. Furthermore, sensitivity analysis was carried out to validate the stability of results. The results showed that the c.963A>G polymorphism is associated with litter size when applying a dominant model (standardized mean difference (SMD) is 0.815, 95 % CI [0.170, 1.461], P value = 0.013) and also with an additive model (SMD = 0.755, 95 % CI [0.111, 1.400], P value = 0.022). However, the effect of c.963A>G polymorphism was not significant under recessive (SMD = 0.186, 95 % CI [−0.195, 4.259], P value = 0.339) and co-dominant (SMD = −0.119, 95 % CI [−0.525, 0.288], P value = 0.568) models. Sensitivity analysis demonstrated that dropping studies with wide confidence intervals affects overall results under the assumption of an additive model. The meta-analysis results revealed that the AA genotype could be positively connected with litter size in goats.
This study was focused on identifying the effects of single nucleotide polymorphisms (SNPs) located on an entire region of the let-7c miRNA gene with consideration of its ability to promote litter size in Markhoz goats. The Markhoz goat, the native breed in Iran, is important for its reproductive traits, such as litter size. DNA polymorphism of let-7c miRNA gene was revealed and considered for further studies for its effect on litter size in Markhoz goats. PCR-SSCP analysis investigated different band patterns for this miRNA; however, sequencing results have detected only an A to T substitution located five nucleotides downstream of the let-7c miRNA gene. The chi-squared test showed that the let-7c miRNA gene locus was out of the Hardy–Weinberg equilibrium (HWE) and has significant effect (p < 0.05). Furthermore, the least-square analysis indicated that the let-7c miRNA gene does not affect prolificacy in the Markhoz goat (p > 0.05). In sum, all loci failed to have a significant effect on the litter size trait (p > 0.05). Moreover, years of kidding and parity had no significant impact on let-7c_S (p > 0.05); however, the let-7c_B affected the litter size trait significantly (p < 0.05). Additionally, binary logistic regression and chi-square analysis revealed that allele A of the detected SNP within 3′ UTR region of the let-7c gene had a non-significant effect on litter size in the studied goats (p > 0.05).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.