Novel copy number variation of the TGFβ3 gene is associated with TGFβ3 gene expression and duration of fertility traits in hens

Abstract

Improvements in the duration of fertility (DF) could increase the interval between successive artificial inseminations, thereby decreasing the cost associated with production of hatching eggs. The molecular mechanisms involved in DF in hens remains under-explored. In this study, expression levels of the transforming growth factor-β genes (TGFβs: TGFβ1, TGFβ2, TGFβ3) were investigated in utero-vaginal junctions (UVJs) of hens with long DF (Group L, n = 10) and short DF (Group S, n = 10). TGFβ1 and 2 tended to exhibit higher expression levels in UVJs from Group L hens. The expression levels of TGFβ3 mRNA and protein were significantly increased in UVJs of hens from Group L compared to hens in Group S. Consistently, six TGFβs downstream genes (DAXX, MEKK1, T-BET, GATA-3, TAK1, and FOXP3) associated with the immune response were found to be significantly differentially expressed in UVJs of Group L than Group S hens. In addition, four SNPs were identified in intron 1 of TGFβ3, and these SNPs were significantly associated with DF traits (P < 0.05). Furthermore, we identified multi-copy and copy number variants (CNVs) in chicken TGFβ3 and later determined significant associations between TGFβ3 CNVs and DF traits in hens. Specifically, TGFβ3 copy number exhibited a significant positive correlation with its expression (P < 0.05). Collectively, our results suggest that chicken DF traits may be regulated by the expression of TGFβ3 in UVJ. Meanwhile, the copy number variation in the TGFβ3 gene identified in this study seems to be one marker for DF traits.

Transcriptome sequencing reveals key potential long non-coding RNAs related to duration of fertility trait in the uterovaginal junction of egg-laying hens

“…Additionally, immune system activity has been implicated in maintaining sperm storage within the SST and at the time of fertilization 15,16 . Likewise, breeder and co-workers proposed that energy derived from mitochondrial fatty acid oxidation might be important for sperm longevity, motility, mobility and storage in the oviduct.…”

Gene co-expression network analysis reveals key potential gene modules in utero-vaginal junction associated with duration of fertility trait of breeder hens

“…Two duration of fertility traits DN and FN were measured in terms (DN = the number of days post-insemination until the last fertile egg was produced; and FN = the number of fertile eggs were produced after a single AI). DN and FN were expressed as average of three measurements 8 .…”

“…Total RNA was isolated using Trizol reagent (Invitrogen, Foster City, CA, USA), following the recommended manufacturers protocol. The quality and quantity of RNA samples were detected by 1.0% agarose gel electrophoresis and absorbance optical density (OD) at a 260/280 nm ratio, respectively 8 . Pair-end 150-bp reads were generated on a Hiseq 2500 sequencing machine at the Shanghai biotechnology corporation.…”

Applications of genomic copy number variations on livestock: A review

“…In addition, CNVs of the genes are associated with reproduction and milk phenotype in cattle (Durán Aguilar et al, 2017;Da Silva et al, 2016b;McCarthy et al, 2012;Prinsen et al, 2017;Sermyagin et al, 2016;Shin et al, 2014;Xu et al, 2016;Yue et al, 2013;Zhou et al, 2018). In chickens, novel CNV of the TGFβ3 gene is associated with duration of fertility traits (Gu et al, 2017). The study of Sasaki et al (2016) identified a deleted-type CNV encompassing ANXA10 in cows that was associated with embryonic mortality at 30-60 days after artificial insemination.…”