RESUMO
The gene encoding heterogeneous ribonucleoprotein (hnRNP) G recently has been mapped to the X chromosome. All mammals have a Y chromosome-encoded homologue of HNRNP G called RBMY, which is implicated with a role in male fertility and is a candidate for the azoospermia factor gene. We have identified a new member of this gene family, HNRNP G-T, and have mapped it as a single-copy gene on chromosome 11. This gene contains an uninterrupted open reading frame and no introns, consistent with derivation from a retroposon. However, unlike many retroposon-derived genes, HNRNP G-T is not a pseudogene. An antiserum raised to the conceptual reading frame of HNRNP G-T showed that it encodes a protein that is highly expressed in germ cells and in particular in the nuclei of meiotic spermatocytes. Surprisingly, although this antiserum was raised against human hnRNP G-T protein, it can also detect a similar protein in the testis of several mammals. This suggests that the protein is highly conserved and that the retrotransposition event generating the HNRNP G-T gene pre-dated at least the common ancestor of mouse and man. The existence of an additional testis-specific hnRNP G family member provides evidence for the importance of these proteins in normal germ cell development.
Assuntos
Evolução Molecular , Retroelementos/genética , Ribonucleoproteínas/biossíntese , Ribonucleoproteínas/genética , Espermatócitos/metabolismo , Cromossomo X , Sequência de Aminoácidos , Animais , Southern Blotting , Bovinos , Núcleo Celular , Cromossomos Humanos Par 11 , Clonagem Molecular , Sequência Conservada , DNA Complementar/metabolismo , Eletroforese em Gel de Poliacrilamida , Biblioteca Gênica , Ligação Genética , Ribonucleoproteínas Nucleares Heterogêneas , Humanos , Hibridização in Situ Fluorescente , Íntrons , Masculino , Meiose/genética , Camundongos , Dados de Sequência Molecular , Fases de Leitura Aberta , Mapeamento Físico do Cromossomo , Ratos , Homologia de Sequência de Aminoácidos , Testículo/metabolismo , Técnicas do Sistema de Duplo-HíbridoRESUMO
OBJECTIVE: To assess the influence of paternal size on birthweight after suitable control for maternal and fetal factors. DESIGN: Prospective observational study. SETTING: Delivery suite, City Hospital, Nottingham. SUBJECTS: 571 husbands/partners of unselected women delivering August 1992 to February 1993. MAIN OUTCOME METHODS: Individualised birthweight ratio and thereby an adjusted birthweight for a typical mother. The results of a multiple regression analysis with the individualised birthweight ratio as the dependent variable. RESULTS: When considered in isolation both paternal height and weight are significantly positively associated with crude and adjusted birthweight (p < 0.01, analysis of variance). Due to correlations of paternal size with maternal size and smoking habit, only paternal height is significant in the multiple regression analysis (p = 0.01). CONCLUSION: If the partner of an average woman is short (mean-2s.d.) then the baby will be 183 g lighter than if he is tall (mean + 2s.d.). This effect of paternal height on birthweight must be genetic and therefore should be taken into account when defining intra-uterine growth retardation and macrosomia.
