Moros-Nicolás C, Leza A, Chevret P, Guillén-Martínez A, González-Brusi L, Boué F, Lopez-Bejar M, Ballesta J, Avilés M, Izquierdo-Rico M J
Department of Cell Biology and Histology, Faculty of Medicine, Biomedical Research Institute of Murcia (IMIB-Arrixaca-UMU), University of Murcia, 30100, Murcia, Spain.
Laboratoire de Biométrie et Biologie Evolutive, UMR5558, CNRS, Université de Lyon, Université Claude Bernard Lyon 1, 69622, Villeurbanne, France.
Reprod Fertil Dev. 2018 Jan;30(2):272-285. doi: 10.1071/RD17022.
The zona pellucida (ZP) is an extracellular envelope that surrounds mammalian oocytes. This coat participates in the interaction between gametes, induction of the acrosome reaction, block of polyspermy and protection of the oviductal embryo. Previous studies suggested that carnivore ZP was formed by three glycoproteins (ZP2, ZP3 and ZP4), with ZP1 being a pseudogene. However, a recent study in the cat found that all four proteins were expressed. In the present study, in silico and molecular analyses were performed in several carnivores to clarify the ZP composition in this order of mammals. The in silico analysis demonstrated the presence of the ZP1 gene in five carnivores: cheetah, panda, polar bear, tiger and walrus, whereas in the Antarctic fur seal and the Weddell seal there was evidence of pseudogenisation. Molecular analysis showed the presence of four ZP transcripts in ferret ovaries (ZP1, ZP2, ZP3 and ZP4) and three in fox ovaries (ZP2, ZP3 and ZP4). Analysis of the fox ZP1 gene showed the presence of a stop codon. The results strongly suggest that all four ZP genes are expressed in most carnivores, whereas ZP1 pseudogenisation seems to have independently affected three families (Canidae, Otariidae and Phocidae) of the carnivore tree.
透明带（ZP）是一种围绕哺乳动物卵母细胞的细胞外被膜。这种被膜参与配子间的相互作用、顶体反应的诱导、多精受精的阻断以及输卵管内胚胎的保护。先前的研究表明，食肉动物的ZP由三种糖蛋白（ZP2、ZP3和ZP4）组成，ZP1是一个假基因。然而，最近一项对猫的研究发现，所有四种蛋白质均有表达。在本研究中，对几种食肉动物进行了计算机模拟和分子分析，以阐明该目哺乳动物的ZP组成。计算机模拟分析表明，在猎豹、大熊猫、北极熊、老虎和海象这五种食肉动物中存在ZP1基因，而在南极毛皮海狮和威德尔海豹中存在假基因化的证据。分子分析显示，雪貂卵巢中有四种ZP转录本（ZP1、ZP2、ZP3和ZP4），狐狸卵巢中有三种（ZP2、ZP3和ZP4）。对狐狸ZP1基因的分析显示存在一个终止密码子。结果强烈表明，所有四种ZP基因在大多数食肉动物中均有表达，而ZP1假基因化似乎独立影响了食肉动物谱系中的三个科（犬科、海狮科和海豹科）。
