Infant loss during and after male replacement in gibbons

According to the sexual selection hypothesis, infanticide during resident male replacement is an adaptive strategy that has evolved because the killing of unweaned offspring sired by previous males shortens the inter‐birth intervals of the mothers whose infants are targeted and thereby increases the reproductive fitness of the perpetrator. To test this hypothesis, we describe previously unreported cases of primary male replacement for two gibbon species (Hylobates lar and Nomascus nasutus), and review all other reported cases of primary male replacement in gibbons. Overall, infants were present in nearly half of all cases (16/33, 48%) and of the 18 infants present during replacement, 50% (N = 9) disappeared within 2 months of the event. In four of the five cases where there was sufficient demographic information to identify the likely sire of the subsequent offspring of females that lost infants, the new male was believed to be the sire. Infants were also less likely to die or disappear if the new male and original resident male were possible kin. However, there was no significant difference in the age of infants between those that died or disappeared following replacement and those that survived to weaning (p = .630). Our review of takeover‐related infant loss in gibbons confirms that periods of male instability are risky for unweaned infants and that replacing males benefit from infant loss. Nevertheless, variability in the context of infant loss and difficulties related to data collection in the field make it difficult to test competing hypotheses concerning the mechanisms and functions of infanticide in the small apes.     

Human bone cell cultures: a new model for studying the mechanism of action of calcitonin

An investigation on cell cultures obtained from temporal human bone fragments showed that they provide a suitable model for studying the mechanism involved in calcitonin action on bone cells. Furthermore they demonstrated: a transitory increase in 45Ca uptake that returned to control values ten minutes after the hormone was added; a relation between 45Ca uptake and increased cAMP concentrations when these were measured at the same time intervals; a reproduction of the salmon calcitonin (sCT) effect after incubation of the cultures with either db-cAMP or db-cGMP and inhibition of 45Ca uptake and parallel decrease in cAMP levels with propanol. These results suggest that in human bone cell cultures, sCT acts as a temporary promoter of 45Ca uptake, probably by activating an adenylate-cyclase system through a beta-receptor.     

Peptide sequence analysis using exopeptidases with molecular analysis of the truncated polypeptides by mass spectrometry

Fast atom bombardment mass spectrometry is used for the analysis of the series of molecular products formed by the cleavage of polypeptide substrates with the exopeptidases carboxypeptidase Y and leucine aminopeptidase. By following the polypeptide molecular species rather than the released residues, sequence information is obtained regardless of the relative rates of cleavage of peptide bonds. In addition, unambiguous assignments of sequence can be made in the presence of multiple identical residues. The lower level of sensitivity for the analysis is in the picomole range. When carboxypeptidase Y is used, the method provides a specific and sensitive method for the sequencing of polypeptides from the C-terminus.     

Identification and comprehensive analysis of the CLV3/ESR‐related (CLE) gene family in Brassica napus L.

• The CLE (CLAVATA3/ESR) gene family, encoding a group of small secretory peptides, plays important roles in cell‐to‐cell communication, thereby controlling a broad spectrum of development processes. The CLE family has been systematically characterized in some plants, but not in Brassica napus.
• In the present study, 116 BnCLE genes were identified in the B. napus genome, including seven unannotated, six incorrectly predicted and five multi‐CLE domain‐encoding genes. These BnCLE members were separated into seven distinct groups based on phylogenetic analysis, which might facilitate the functional characterization of the peptides.
• Further characterization of CLE pre‐propeptides revealed 31 unique CLE peptides from 45 BnCLE genes, which may give rise to distinct roles of BnCLE and expansion of the gene family. The biological activity of these unique CLE dodecamer peptides was tested further through in vitro peptide assays. Variations in several important residues were identified as key contributors to the functional differentiation of BnCLE and expansion of the gene family in B. napus. Expression profile analysis helped to characterize possible functional redundancy and sub‐functionalization among the BnCLE members.
• This study presents a comprehensive overview of the CLE gene family in B. napus and provides a foundation for future evolutionary and functional studies.

     

Interleukin 3 augments the murine primary cytolytic T lymphocyte response to allogeneic tumor cells

The primary anti-H-2k allospecific cytolytic T lymphocyte (CTL) response by BALB/c (H-2d) spleen cells in vitro to x-irradiated RDM4 (H-2k) tumor cells is weak. This response has been shown to be augmented by CTL helper factor (CHF), a factor present in supernatants of spleen cells cultured with Sendai virus (SC-CM). Conditioned medium from WEHI-3 cells (WEHI-CM) also contains activity that augments the BALB/c anti- RDM4 CTL response. Attempts to separate the CHF activity from interleukin 3 (IL 3), also present in WEHI-CM, were unsuccessful. Purified IL 3 was then tested, and was found to increase the BALB/c anti- RDM4 CTL response by five- to 10-fold. IL 3 is apparently the only material in WEHI-CM that is active in this assay. The response is apparently a classical CTL response because: 1) the effector cells are sensitive to monoclonal anti-Thy-1.2 antibody plus C; 2) the response is dependent on antigen stimulation, and it peaks on day 5 or 6 of culture; and 3) the effector cells are specific for H-2k targets. IL 3 must be added very early during the in vitro culture period for maximal augmentation of the response, consistent with possible action of IL 3 as a differentiation factor.     

The human mineralocorticoid receptor gene (MLR) is located on chromosome 4 at q31.2

The gene for the human mineralocorticoid receptor (MLR) was previously localized to chromosome 4. Here, we have localized this gene to 4q31.2 by in situ hybridization. This precise mapping of MLR will assist in the linkage analysis and genetic characterization of pseudohypoaldosteronism, an autosomal recessive disorder which likely results from a defect in the MLR gene.