Postnatal expression of IGF2 is the norm in amniote vertebrates
Postnatal expression of IGF2 is the norm in amniote vertebrates
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DOI：
10.1098/rspb.2021.2278
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发表时间：
2022-02-23
影响因子：
4.7
通讯作者：
Schwartz, Tonia S.
中科院分区：
文献类型：
--
作者：
Beatty, Abby;Rubin, Alexander M.;Schwartz, Tonia S.
胰岛素和胰岛素样信号（IIS）网络在介导几种生活史特征，包括生长，繁殖和衰老中起着重要作用。虽然胰岛素样生长因子（IGFs）1和2都是脊椎动物IIS网络中的关键激素，但对青少年和成年人IGF 2的研究在很大程度上被忽视，因为对啮齿动物的早期生物医学研究发现IGF 2出生后的表达可以忽略不计。在这里，我们挑战这一假设，并询问在何种程度上IGF 2的表达在出生后的生活中跨越蜥蜴，通过量化IGF 1和IGF 2的相对基因表达，使用公开的RNAseq数据82蜥蜴物种和定量聚合酶链反应在胚胎，少年和成年阶段的肝脏cDNA两种蜥蜴，鸟类和小鼠物种。我们发现：（i）IGF 2在出生后跨哺乳动物物种和生命阶段表达，通常相对表达高于IGF 1，与啮齿动物模型相矛盾;（ii）啮齿动物出生后IGF 2表达的缺乏是由于系统发育的位置，而不是近亲繁殖或人工选择;（iii）成年IGF 2表达在某些物种中具有性别偏见。我们的研究结果表明，IGF 2的表达是典型的在整个生命周期中，这表明一个全面的了解介导的生活史特征的变化的机制将需要研究，测量两个IGFs。
The insulin and insulin-like signalling (IIS) network plays an important role in mediating several life-history traits, including growth, reproduction and senescence. Although insulin-like growth factors (IGFs) 1 and 2 are both key hormones in the vertebrate IIS network, research on IGF2 in juveniles and adults has been largely neglected because early biomedical research on rodents found negligible IGF2 postnatal expression. Here, we challenge this assumption and ask to what degree IGF2 is expressed during postnatal life across amniotes by quantifying the relative gene expression of IGF1 and IGF2 using publicly available RNAseq data for 82 amniote species and quantitative polymerase chain reaction on liver cDNA at embryonic, juvenile and adult stages for two lizard, bird and mouse species. We found that (i) IGF2 is expressed postnatally across amniote species and life stages-often at a higher relative expression than IGF1, contradicting rodent models; (ii) the lack of rodent postnatal IGF2 expression is due to phylogenetic placement, not inbreeding or artificial selection; and (iii) adult IGF2 expression is sex-biased in some species. Our results demonstrate that IGF2 expression is typical for amniotes throughout life, suggesting that a comprehensive understanding of the mechanisms mediating variation in life-history traits will require studies that measure both IGFs.