Structure and sequence of the myosin alkali light chain gene expressed in adult cardiac atria and fetal striated muscle

Mammalian cardiac muscle contains two myosin alkali light chains which are the major isoforms present in either atrial (MLC1A) or ventricular (MLC1V) muscle, and which are different from the fast skeletal muscle isoforms (MLC1F and MLC3F). The atrial isoform is also expressed in fetal skeletal and fetal ventricular muscle, where this isoform is also described as the fetal isoform MLC1emb. We have previously isolated a cDNA clone encoding part of the mouse MLC1A/MLC1emb isoform and have used this clone to demonstrate the identity of MLC1A and MLC1emb in the mouse. To date no information on the amino acid sequence of this mammalian atrial/fetal isoform has been available. Here we present the complete structure and sequence of the mouse MLC1A/MLC1emb gene, together with the predicted amino acid sequence of this isoform. Comparison of the MLC1A/MLC1emb gene and polypeptide with those of MLC1F and MLC1V suggests that MLC1A/MLC1emb and MLC1V were generated from a common ancestral gene. The NH2-terminal region of MLC1A/MLC1emb, thought to be involved in the actomyosin interaction, shows conservation with MLC1V but not with MLC1F suggesting a shared functional domain in these cardiac isoforms. Comparison with the chicken embryonic MLC (L23) suggests that although MLC1A/MLC1emb and L23 show very different patterns of expression, both during development and in the adult, they probably represent the homologous gene in these two species.     

The effect of prior housing conditions on the sexual receptivity of females of the blowfly,Lucilia cuprina

Sexual receptivity in sugar-and-water-fed females of the anautogenous blowfly Lucilia cuprinawas low when they had been housed in groups but high when they had been housed singly. Females were completely unreceptive on the second and third days after emergence, irrespective of housing conditions. There after receptivity increased but more rapidly in the singly housed females. Experiments in which females were housed singly for some days and then in groups, or vice versa, showed that receptivity could be influenced by housing conditions experienced both over the first 5 days after emergence and later in life.     

Mesocestoides corti in the rat: Comparisons of Mesocestoides corti infections in rats and mice

Infections of M. corti in rats were compared with those in mice. The recoveries of parasites and their distribution were examined for 60 days after infection. During this period continuous and extensive multiplication occurred in mice. In rats there was an initial multiplication of tetrathyridia in the first 10 days followed by a decline in numbers. The relative distribution of tetrathyridia between the peritoneal cavity and liver was similar in both hosts.     

Contributions of Mamu-A*01 Status and TRIM5 Allele Expression,But Not CCL3L Copy Number Variation,to the Control of SIVmac251 Replication in Indian-Origin Rhesus Monkeys

CCL3 is a ligand for the HIV-1 co-receptor CCR5. There have recently been conflicting reports in the literature concerning whether CCL3-like gene (CCL3L) copy number variation (CNV) is associated with resistance to HIV-1 acquisition and with both viral load and disease progression following infection with HIV-1. An association has also been reported between CCL3L CNV and clinical sequelae of the simian immunodeficiency virus (SIV) infection in vivo in rhesus monkeys. The present study was initiated to explore the possibility of an association of CCL3L CNV with the control of virus replication and AIDS progression in a carefully defined cohort of SIVmac251-infected, Indian-origin rhesus monkeys. Although we demonstrated extensive variation in copy number of CCL3L in this cohort of monkeys, CCL3L CNV was not significantly associated with either peak or set-point plasma SIV RNA levels in these monkeys when MHC class I allele Mamu-A*01 was included in the models or progression to AIDS in these monkeys. With 66 monkeys in the study, there was adequate power for these tests if the correlation of CCL3L and either peak or set-point plasma SIV RNA levels was 0.34 or 0.36, respectively. These findings call into question the premise that CCL3L CNV is important in HIV/SIV pathogenesis.     

A model describing the kinetics of mating in Drosophila

The kinetics of mating in species of Drosophila that copulate for periods of time greater than the duration of experimental observation can be described precisely by an equation that combines second order reaction kinetics with the exponential decay of a lag factor. The two rate constants for this kinetic system were estimated from mating data using a wild-type D. simulans strain, a wild-type D. melanogaster strain, and vestigial mutant D. melanogaster males with wild-type females. The results confirm the applicability of second order kinetics, and demonstrate the usefulness of the model in comparisons of mating rates among strains of flies. In most cases, the model explains more than 95% of the variance in the data, and in addition sheds light on the mechanics of the process of mating.     

13C nuclear magnetic resonance spectra of 1,2-dioctadec-cis-enoyl-sn-glycero-3-phosphorylcholines.

The 13C NMR spectra of all sixteen 1,2-dioctade-cis-enoyl-sn-glycero-3-phosphorylcholines have been obtained. Resonance lines of the olefinic, methylene, methyl and carboxyl carbon nuclei are sufficiently characteristic to permit unequivocal designation of double bond position for each isomer. Two resonances of the sn-glycero-3-phosphorylcholine structure have been reassigned.