| Home | << 1 2 3 4 >> |
|
Hostikka, S. L., Eddy, R. L., Byers, M. G., Hoyhtya, M., Shows, T. B., & Tryggvason, K. (1990). Identification of a distinct type IV collagen alpha chain with restricted kidney distribution and assignment of its gene to the locus of X chromosome-linked Alport syndrome. Proc. Natl. Acad. Sci. U.S.A., 87(4), 1606–1610.
Abstract: We have identified and extensively characterized a type IV collagen alpha chain, referred to as alpha 5(IV). Four overlapping cDNA clones isolated contain an open reading frame for 543 amino acid residues of the carboxyl-terminal end of a collagenous domain, a 229-residue carboxyl-terminal noncollagenous domain, and 1201 base pairs coding for a 3' untranslated region. The collagenous Gly-Xaa-Yaa repeat sequence has five imperfections that coincide with those in the corresponding region of the alpha 1(IV) chain. The noncollagenous domain has 12 conserved cysteine residues and 83% and 63% sequence identity with the noncollagenous domains of the alpha 1(IV) and alpha 2(IV) chains, respectively. The alpha 5(IV) chain has less sequence identity with the putative bovine alpha 3(IV) and alpha 4(IV) chains. Antiserum against an alpha 5(IV) synthetic peptide stained a polypeptide chain of about 185 kDa by immunoblot analysis and immunolocalization of the chain in human kidney was almost completely restricted to the glomerulus. The gene was assigned to the Xq22 locus by somatic cell hybrids and in situ hybridization. This may be identical or close to the locus of the X chromosome-linked Alport syndrome that is believed to be a type IV collagen disease.
Keywords: Amino Acid Sequence; Base Sequence; Chromosome Mapping; Cloning, Molecular; Collagen/*genetics; Epitopes/analysis; Female; Fluorescent Antibody Technique; Gene Library; *Genes; Humans; Immunoblotting; Kidney/cytology/*metabolism; Macromolecular Substances; Molecular Sequence Data; Nephritis, Hereditary/*genetics; Oligopeptides/chemical synthesis/immunology; Placenta/metabolism; Pregnancy; Restriction Mapping; Sequence Homology, Nucleic Acid; *X Chromosome
|
|
Bartosova, J., Komarkova, M., Dubcova, J., Bartos, L., & Pluhacek J. (2012). Nursing behaviour in pregnant domestic mares (Equus caballus): Can they cope with dual maternal investment? In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: Among mammals, lactation is the most energy demanding part of parental care and so parentoffspring conflict should arise over milk provided by the mother. Mother and offspring should disagree over the length and amount of the milk provision. We focused on effect of pregnancy on suckling behaviour variables as indicators of mother-offspring conflict in domestic horses. We presumed shorter suckling bouts and higher rates of rejected and/or terminated suckling in pregnant mares compared to non-pregnant ones. Increasing conflict over amount of maternal investment between mother and her young are to be expected because of her parallel investment into a nursed foal and a foetus. Eight groups of loose housed lactating mares with foals of Kladruby horse were studied at the National Stud Kladruby nad Labem (Czech Republic) from deliveries to abrupt weaning (at the age of 127 to 210 days). We recorded 10 848 suckling solicitations of 79 mare-foal pairs, from which 10 607 resulted in a suckling bout. In 41 cases a nursing mare became pregnant during lactation. We found no significant effect of pregnancy either on probability of the mother rejecting suckling solicitation of her foal or probability that she terminated a suckling bout. However the overall effect of mother’s pregnancy on suckling bout duration was not significant, there were considerable differences in pregnant and non-pregnant mares according to who terminated a suckling bout, whether the mother or the foal (F(1, 9776) = 12.1, P < 0.001). In case it was the mother then the suckling bout was longer if she was pregnant (65.36 ± 1.25 s) than barren (60.55 ± 1.36 s). We found no impact of pregnancy on duration of suckling bouts terminated by the foal. Further, nursing a foal during the first two trimesters of pregnancy had no negative impact on birth weight of the foetus. In conclusion, we found not higher, but a lower mother-offspring conflict in pregnant than in non-pregnant lactating mares while expecting just the opposite. We suggest that pregnant mares compensate their nursed foals during intensive stages of lactation through a relaxed mother-offspring conflict for later decrease in investment due to increasing demands of the foetus and/or for the shorter period of milk supply. Our results (partly published in Bartosova et al. 2011, PLoS ONE 6(8): e22068) are of high importance in horse breeding. One of the main arguments for early weaning of the foals is regeneration of their pregnant mothers before upcoming delivery. Here we present evidence that a pregnant mare “counts” with her dual maternal investment and “employs” evolutionary mechanisms enabling her to rear a vital foetus. From this point of view there is no objective reason for stressful weaning of her nursed offspring practised in conventional breeding. Supported by AWIN, EU FP7 project No. 266213.
|