Dierking Shannon L, Morton Jodi M, Clapper Jeffrey A, Gonda Michael G, Pinilla Juan C, Levesque C L
CSA Animal Nutrition, Dayton, OH, U.S.A.
Department of Agricultural Sciences, Southern University and A&M College, Baton Rouge, LA, U.S.A.
Anim Reprod. 2024 Dec 20;22(1):e20240056. doi: 10.1590/1984-3143-AR2024-0056. eCollection 2025.
Early puberty is associated with improved long-term reproductive performance. Predicting who will achieve early puberty is limited to intensive, invasive serial blood collections for measurement of reproductive hormones. The vaginal genome during pubertal development has potential as biomarkers of early estrus in the pre-pubertal period. Pre-pubertal gilts (n =13) were followed from d74 ± 3 of age until first estrus or d214 ± 1 of age. Blood, vaginal epithelia, and anogenital distance were collected at five timepoints during reproductive development (d74, d104, d130, d160 and first estrus or end of trial). Total RNA was isolated from vaginal epithelia and relative gene expression of two toll-like receptors (TLR-4 and TLR-5), tacykinin precursor-3 (TAC-3), insulin-like growth factor-1 (IGF-1), and estrogen receptor (ERα)-alpha was quantified by real time RT-PCR, relative to expression of RPLP0. Four gilts exhibited estrus early (< d184), 3 were average (d194 to 195), 3 were late (d203 to 213), and 3 were deemed anestrus. Comparison of expression of each gene relative to d70 was performed using the PCR package in RStudio (version 1.2.5025) and Fisher's exact t-test for TLR-4, TLR-5 and TAC-3, and ANOVA for ER-alpha and IGF-1. Correlation analysis examined the relationship between anogenital distance and age at first estrus. A single blood draw for serum progesterone was obtained 8 days after recorded first estrus or end of trial; the presence of serum progesterone supports the visual identification of standing estrus. Expression of IGF-1 and TAC-3 were up-regulated 9- and 7-fold, respectively at d160 ( < 0.05). Expression of ERα tended to be upregulated 3-fold at d104 ( = 0.08) and expression of TLR-4 and TLR-5 was not detected until first estrus. Anogenital distance was positively correlated to the first estrus. These transcripts associated with reproduction warrant further investigation into use as biomarkers to detect early estrus.
青春期提前与长期生殖性能改善相关。预测谁会青春期提前仅限于通过密集、侵入性的系列采血来测量生殖激素。青春期发育期间的阴道基因组有潜力作为青春期前早期发情的生物标志物。对13头青春期前后备母猪从74±3日龄开始跟踪，直至首次发情或214±1日龄。在生殖发育的五个时间点（74日龄、104日龄、130日龄、160日龄以及首次发情或试验结束时）采集血液、阴道上皮和肛门生殖距离。从阴道上皮中分离出总RNA，通过实时RT-PCR对两种Toll样受体（TLR-4和TLR-5）、速激肽前体-3（TAC-3）、胰岛素样生长因子-1（IGF-1）和雌激素受体（ERα）的相对基因表达进行定量，相对于核糖体蛋白L30（RPLP0）的表达。4头后备母猪发情早（<184日龄），3头为平均水平（194至195日龄），3头较晚（203至213日龄），3头被判定为乏情。使用RStudio（版本1.2.5025）中的PCR软件包以及针对TLR-4、TLR-5和TAC-3的Fisher精确t检验以及针对ER-α和IGF-1的方差分析，对每个基因相对于70日龄的表达进行比较。相关性分析研究了肛门生殖距离与首次发情年龄之间的关系。在记录的首次发情或试验结束8天后采集一次血清孕酮血样；血清孕酮的存在支持对静立发情的视觉识别。IGF-1和TAC-3的表达在160日龄时分别上调了9倍和7倍（<0.05）。ERα的表达在104日龄时倾向于上调3倍（=0.08），TLR-4和TLR-5的表达直到首次发情时才被检测到。肛门生殖距离与首次发情呈正相关。这些与生殖相关的转录本值得进一步研究用作检测早期发情生物标志物的用途。
