Genome-Wide Linkage Analysis Identifies Loci for Testicle and Ovary Traits in Chickens

Melatonin alleviates glyphosate-induced testosterone synthesis inhibition via targeting mitochondrial function in roosters

Glyphosate (GLY) is a widely used herbicide that has been revealed to inhibit testosterone synthesis in humans and animals. Melatonin (MET) is an endogenous hormone that has been demonstrated to promote mammalian testosterone synthesis via protecting mitochondrial function. However, it remains unclear whether MET targets mitochondria to alleviate GLY-inhibited testosterone synthesis in avian. In this study, an avian model using 7-day-old rooster upon chronic exposure to GLY with the treatment of MET was designed to clarify this issue. Data first showed that GLY-induced testicular Leydig cell damage, structural damage of the seminiferous tubule, and sperm quality decrease were mitigated by MET. Transcriptomic analyses of the testicular tissues revealed the potentially critical role of mitophagy and steroid hormone biosynthesis in the process of MET counteracting GLY-induced testicular damage. Also, validation data demonstrated that the inhibition of testosterone synthesis due to GLY-induced mitochondrial dynamic imbalance and concomitant Parkin-dependent mitophagy activation is alleviated by MET. Moreover, GLY-induced oxidative stress in serum and testicular tissue were significantly reversed by MET. In summary, these findings demonstrate that MET effectively ameliorates GLY-inhibited testosterone synthesis by inhibiting mitophagy activation, which provides a promising remedy for the application of MET as a potential therapeutic agent to antagonize reproductive toxicity induced by GLY and similar contaminants.

Analysis of the differentially expressed genes in the combs and testes of Qingyuan partridge roosters at different developmental stages

BACKGROUND

The sexual maturity of chickens is an important economic trait, and the breeding of precocious and delayed puberty roosters is an important selection strategy for broilers. The comb serves as an important secondary sexual characteristic of roosters and determines their sexual precocity. Moreover, comb development is closely associated with gonad development in roosters. However, the underlying molecular mechanism regulating the sexual maturity of roosters has not yet been fully explored.

RESULTS

In order to identify the genes related to precocious puberty in Qingyuan partridge roosters, and based on the synchrony of testis and combs development, combined with histological observation and RNA-seq method, the developmental status and gene expression profile of combs and testis were obtained. The results showed that during the early growth and development period (77 days of age), the development of combs and testis was significant in the high comb (H) group versus the low comb (L) group (p < 0.05); however, the morphological characteristic of the comb and testicular tissues converged during the late growth and development period (112 days of age) in the H and L groups. Based on these results, RNA-sequencing analysis was performed on the comb and testis tissues of the 77 and 112 days old Qingyuan Partridge roosters with different comb height traits. GO and KEGG analysis enrichment analysis showed that the differentially expressed genes were primarily enriched in MAPK signaling, VEGF signaling, and retinol metabolism pathways. Moreover, weighted correlation network analysis and module co-expression network analysis identified WNT6, AMH, IHH, STT3A, PEX16, KPNA7, CATHL2, ROR2, PAMR1, WISP2, IL17REL, NDRG4, CYP26B1, and CRHBP as the key genes associated with the regulation of precocity and delayed puberty in Qingyuan Partridge roosters.

CONCLUSIONS

In summary, we identified the key regulatory genes of sexual precocity in roosters, which provide a theoretical basis for understanding the developmental differences between precocious and delayed puberty in roosters.

Trehalose prevents glyphosate-induced testicular damage in roosters via its antioxidative properties

Glyphosate (GLY), an active ingredient of the most commonly used herbicide, when in crops and feed, is deleterious to male reproductive health. Trehalose (Tre), a naturally non-reducing disaccharide, is shown to counteract the adverse stresses due to its antioxidation effect. Thus, this study was designed to investigate whether Tre can improve GLY-induced testicular damage via suppressing oxidative stress. 60 healthy Hy-Line Brown breeder roosters were utilized to assess the protective effects of Tre supplementation against testicular oxidative damage caused by GLY. Data showed that Tre administration significantly alleviated GLY- induced reduction in testis weight, decreased GLY level in the testis tissues, and alleviated GLY-caused testicular pathological damage. Concurrently, GLY treatment significantly elevated serum malondialdehyde (MDA) and testicular reactive oxygen species (ROS) levels, decreased serum total anti-oxidation capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels, which were all notably reversed by Tre administration. Moreover, GLY- inhibited nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in rooster testis, a master regulator of oxidative stress, was markedly recovered by Tre administration. In summary, these findings demonstrated that Tre can prevent GLY-induced testicular damage in roosters by ameliorating oxidative stress.

Identification of Key Candidate Genes in Runs of Homozygosity of the Genome of Two Chicken Breeds, Associated with Cold Adaptation

Simple Summary

The search for genomic regions related to adaptive abilities preserved in the chicken gene pool of two breeds, which have not been under intensive selection pressure, is of great importance for breeding in the future. This study aimed to identify key candidate genes associated with the adaptation of chickens to cold environments (using the example of the Russian White breed) by using molecular genetic methods. A total of 12 key genes on breed-specific ROH (runs of homozygosity) islands were identified, which may be potential candidate genes associated with the high level of adaptability of chickens to cold environments in the early postnatal period. These genes were associated with lipid metabolism, maintaining body temperature in cold environments, non-shivering thermogenesis and muscle development and are perspectives for further research.

Abstract

It is well known that the chicken gene pools have high adaptive abilities, including adaptation to cold environments. This research aimed to study the genomic distribution of runs of homozygosity (ROH) in a population of Russian White (RW) chickens as a result of selection for adaptation to cold environments in the early postnatal period, to perform a structural annotation of the discovered breed-specific regions of the genome (compared to chickens of the Amroks breed) and to suggest key candidate genes associated with the adaptation of RW chickens to cold environments. Genotyping of individual samples was performed using Illumina Chicken 60K SNP BeadChip^® chips. The search for homozygous regions by individual chromosomes was carried out using the PLINK 1.9 program and the detectRuns R package. Twelve key genes on breed-specific ROH islands were identified. They may be considered as potential candidate genes associated with the high adaptive ability of chickens in cold environments in the early postnatal period. Genes associated with lipid metabolism (SOCS3, NDUFA4, TXNRD2, IGFBP 1, IGFBP 3), maintaining body temperature in cold environments (ADIPOQ, GCGR, TRPM2), non-shivering thermogenesis (RYR2, CAMK2G, STK25) and muscle development (METTL21C) are perspectives for further research. This study contributes to our understanding of the mechanisms of adaptation to cold environments in chickens and provides a molecular basis for selection work.

An integrated analysis of testis miRNA and mRNA transcriptome reveals important functional miRNA-targets in reproduction traits of roosters

The reproductive efficiency of roosters is an important trait in poultry production; however, the molecular mechanisms underlying this trait are not clearly understood. Here, we compared the mRNA and microRNA (miRNA) transcriptomes of testis from roosters with divergent sperm motility. A total of 302 differentially expressed genes (DEGs), including 182 upregulated genes and 120 downregulated genes, were identified in high sperm motility groups compared with low sperm motility groups. A subset of these DEGs related to steroid hormone biosynthesis and thus could be important for spermatogenesis. Additionally, we detected 13 differentially expressed miRNAs (DEMs) between two groups, and target gene prediction indicated seven of these could be associated with spermatogenesis. Based on a comprehensive analysis of these transcriptomes, miRNA-mRNA interaction networks were constructed. Six DEGs were predicted to be regulated by DEMs. Subsequently, we validated the negative regulation of family with sequence similarity 84, member A (FAM84A) by miR-215 using a dual-luciferase reporter system. These results provide new insights into the molecular profile of the testis and identify genes that may determine sperm motility in chickens.