Rato de campo: Diferenzas entre revisións

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Miguelferig (conversa | contribucións)
Miguelferig (conversa | contribucións)
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== Reprodución ==
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The wood mouse has a [[breeding season]] from February to October in which multiple matings occur between males and females, resulting in scramble competition. Such behavioral characteristics result in [[sperm competition]] and multiple paternity litters. The society is [[polygyny|polygynous]] with [[copulation]] resulting from scramble competition during reproductive periods. Males possess a [[wikt:sac|sac]] known as the cauda epididymis, which stores sperm and lies underneath the [[scrotum|scrotal]] protrusion. Temperature regulation ensures maximum sperm output.
 
O rato de campo ten unha [[estación reprodutora]] de febreiro a outubro na cal ocoren moitos apareamentos, e competición embarullada para aparearse. Tal comportamento característico ten como resultado nunha [[competición de esperma]] e camadas de varias paternidades. A sociedade destes ratos é [[polixinia|polixínica]] e a [[copulación]] é o resultado desta competición durante os períodos reprodutores.
One interesting observation about the species, in particular the males, is the morphology of the [[spermatozoa]]. They develop falciform (sickle-shaped) heads after [[meiosis]] and before [[spermiation]] (release during [[ejaculation]]). The hook located at the tip of the head adheres to the surface of the head prior to deployment. Propidium iodide staining revealed that only the basal surface of the hook is of nuclear origin.<ref name="Moore2002">{{cite journal |last=Moore |first=Harry |year=2002 |title=Exceptional sperm cooperation in the wood mouse |journal=Nature |volume=418 |issue=6894 |pages=174–177 |doi=10.1038/nature00832 |url= |accessdate= |pmid=12110888 |display-authors=etal}}</ref> These apical hooks are deployed in female reproductive tract (mechanism responsible involved the remodeling of actin filaments in the hook).<ref name="Moore2002" /> Deployed apical hooks combine with apical hooks and flagella of other spermatozoa. The aggregates of spermatozoa that result form "mobile trains", which have experimentally been determined to possess better motility in the female reproductive tract.<ref name="Moore2002" /> The mobility of these mobile trains was also found to be influenced by premature acrosome reactions, [[altruism|altruistic]] acts performed by some spermatozoa for the benefit of other genetically similar [[gametocyte]]s. This altruism follows a "[[Green-beard effect|green beard]]" mechanism in which spermatozoa discern the genetic similarity of surrounding gametocytes (such mechanisms are rare because they must code for a recognizable phenotype, as well as response mechanisms). Once spermatozoa of similar genotypes are identified, altruism genes are turned on to elicit a response that seeks to conserve the genes present in the other cell, even if it results in the destruction of the cell performing the action.
 
Unha observación interesante sobre a especie relativa aos machos é a morfoloxía dos [[espermatozoide]]s. Teñen cabezas falciformes (con forma de media lúa ou fouce) despois da [[meiose]] e antes da [[espermiación]]. Teñen un gancho localizado no extremo da cabeza do espermatozoide. A tinguidura con ioduro de propidio revela que só a superficie basal do gancho é de orixe nuclear.<ref name="Moore2002">{{cite journal |last=Moore |first=Harry |year=2002 |title=Exceptional sperm cooperation in the wood mouse |journal=Nature |volume=418 |issue=6894 |pages=174–177 |doi=10.1038/nature00832 |url= |accessdate= |pmid=12110888 |display-authors=etal}}</ref> Eses ganchos apicais son despregados no tracto reprodutor feminino (o mecanismo responsable implicado é a remodelación dos filamentos de [[actina]] do gancho).<ref name="Moore2002" /> Os ganchos apicais despregados combínanse cos ganchos apicais e os [`flaxelo]]s doutros espermatozoides. Os espermatozoides agréganse deste modo e forman "trens móbiles", que se determinou experimentalmente que posúen unha mellor mobilidade dentro do tracto reprodutor da femia que os non agregados.<ref name="Moore2002" /> A mobilidade destes trens móbiles está influenciada pola reacción acrosómica prematura, actos altruístas realizados por algúns espermatozoides que benefician a outros [[gametocito]]s xeneticamente similares. Este altruísmo segue un mecanismo de "[[efecto barba verde]]" no cal os espermatozoides distinguen a semellana xenética dos gametocitos ue os rodean. Unha vez que se identifican os espermatozoides de [[xenotipo]]s similares, os xenes para o altruísmo son activados para provocar unha resposta que busca conservar os xenes presentes na outra célula, mesmo se ten como resultado a destrución da célula que realizou a acción.
The [[gestation]] period of wood mice is of 25–26 days and each female produces on average five young. The offspring become independent after about three weeks and become sexually active after two months.
 
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O período de [[xestación]] do rato de campo é de 25 ou 26 días e cada femia pare como media cinco fillos. A descendenci faise independente pasadas tres semanas e faise sexualmente activo despois de dous meses.
 
== Galería ==