Ce processus est essentiel pour égaliser le dosage des produits des gènes liés à l'X, entre les mammifères mâles et femelles. L'inactivation du chromosome X (ICX) est un paradigme de régulation épigénétique impliquant des lARNnc. Nos connaissances sur ces lARNnc proviennent de l'étude d'une infime fraction de ces molécules, révélant leur implication dans de nombreux processus cellulaires, notamment la régulation de l'expression génique. L'évolution des études transcriptomiques a révélé une transcription pervasive chez les eucaryotes, produisant de nombreux ARN non codants, et notamment des longs ARNs non codants (lARNnc). Since the combination of XO and trisomy 16 does not severely affect early mouse development, it is likely that regulatory mechanisms essential for early embryogenesis do not function correctly in XnX16 embryos due to activity of the extra X chromosome segment of X16. Developmental abnormalities found in XnX16 embryos include: (1) growth retardation detected as early as stage 9, (2) continual loss of embryonic ectoderm cells either by death or by expulsion into the proamniotic cavity, (3) underdevelopment of the ectoplacental cone throughout the course of development, (4) very limited, if any, mesoderm formation, (5) failure in early organogenesis including the embryo, amnion, chorion and yolk sac. Since X chromosome inactivation does not occur in these embryos, probably due to the lack of the inactivation center on X16, XnX16 embryos are functionally disomic for the proximal 63% of the X chromosome and trisomic for the distal segment of chromosome 16. “In fact, my son was wanting to have him in one of his classes, because he is so involved with the kids and then to hear this, it’s just unbelievable.Matings between female mice carrying Searle's translocation, T(X 16)16H, and normal males give rise to chromosomally unbalanced zygotes with two complete sets of autosomes, one normal X chromosome and one X16 translocation chromosome (XnX16 embryos).
Supportive of the kids,” Kenneth Dinsdale, a veritable parent on the street, told KTRK-TV. “We always would see him at activities, as far as sports, athletic stuff, and stuff like that. Local parents are, of course, shocked at the allegations. He has been employed by the school district since 2009.
It’s not clear if he is still receiving a paycheck. 17, just before winter break, Tate was placed on administrative leave. They were also quick to note that no incidents have been alleged to have happened on school property. School officials told the Chronicle that the history teacher is very popular among students. The girl also sent photos to the 36-year-old teacher of herself in lingerie. These records, they say, provide evidence that the teacher and the student had engaged in sexual intercourse.
Investigators obtained the records of phone calls and texts between Tate and the 16-year-old girl.
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