Does hard mast production affect patterns of cementum annuli formation in premolar teeth of Asian black bears (Ursus thibetanus)?
Does hard mast production affect patterns of cementum annuli formation in premolar teeth of Asian black bears (Ursus thibetanus)?
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DOI：
10.1371/journal.pone.0211561
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发表时间：
2019-02-04
期刊：
影响因子：
3.7
通讯作者：
Koike, Shinsuke
中科院分区：
文献类型：
--
作者：
Tochigi, Kahoko;Aoki, Yukino;Koike, Shinsuke
哺乳动物牙骨质环的宽度受哺乳动物营养的影响。生殖压力已被认为是减少导致更窄的牙骨质环宽度在女性亚洲黑熊（Ursus thibetanus）的宽度;然而，秋季的食物供应强烈影响熊的营养，并可能影响牙骨质宽度。本研究的目的是测试如何牙骨质环宽度和假环的形成影响硬桅杆生产。我们建立了两个假设：（1）营养条件不佳的贫乳年牙骨质环宽度变窄;（2）假牙骨质环在贫乳年更易发生。我们使用雄性熊的牙齿样本，以避免生殖的影响，并将宽度数据分为“成年”和“亚成年”组。我们计算了比例宽度指数（PWI），并使用线性混合模型来估计桅杆对PWI的影响。广义线性混合模型估计了主效应对假环频率的影响。真环宽度和假环的形成没有显着的关系，肥大生产的成人。在亚成体中，肥大细胞生成不良对假环形成的负面影响很小。这些新的数据解决了以前的问题，使我们能够推断，牙骨质环宽度是一个可靠的指标，繁殖成功的雌性熊。
Cementum annuli widths in mammals are is influenced by the nutrition of mammals. Reproductive stress has been is suggested to reduce the width of lead to narrower cementum annuli widths in female Asian black bears (Ursus thibetanus); however, food availability in autumn strongly impacts bear nutrition and likely impacts cementum widths as well. This study aimed to test how cementum annuli widths and the formation of false annuli were influenced by hard mast production. We established two hypotheses: (1) cementum annuli widths become narrower in poor mast years owing to inadequate nutritional conditions and (2) false annuli occur more frequently in poor mast years. We used teeth samples from male bears to avoid reproductive influences and separated width data into "adult" and "subadult" groups. We calculated the proportional width index (PWI) and used linear mixed models to estimate the masting effects on PWI. Generalized linear mixed models estimated the masting effects on false annuli frequency. True annuli widths and false annuli formation showed no significant relationship with mast production in adults. In subadults, poor mast production weak negative influence on false annuli formation. These new data resolve previous questions, allowing us to deduce that cementum annuli widths are a reliable index of reproductive success in female bears.