Functions of post‐conflict affiliation with a bystander differ between aggressors and victims in Japanese macaques

Post‐conflict affiliative interactions with a bystander, an uninvolved third party, have been reported in several species. The functions of these interactions could vary depending on whether the individual was an aggressor or a victim in a conflict. We examined the occurrence of and three potential functions for bystander affiliation—substitute for reconciliation, self‐protection and consolation (stress reduction)—in a free‐ranging group of Japanese macaques. We predicted that in this despotic species, the function of bystander affiliations for victims was self‐protection, whereas this was not so for aggressors. We found that compared to control situations, both aggressors and victims engaged in bystander affiliation soon after a conflict, confirming the occurrence of bystander affiliation. Victims were less likely to receive further aggression when bystander affiliation occurred than when no such interaction occurred, consistent with the explanation that post‐conflict bystander affiliation functions as self‐protection for victims. Aggressors were less likely to perform self‐scratching, an indicator of post‐conflict stress, when bystander affiliation occurred. This suggests that such affiliations benefited aggressors by reducing stress. Self‐scratching was not less frequent after affiliation with a bystander who was familiar with the former opponent, indicating that substitute reconciliation did not apply for either aggressors or victims. When bystander affiliation occurred, the bystander was a more familiar individual for aggressors and victims than the former opponent was. In conclusion, aggressors benefited in stress reduction, whereas victims benefited in self‐protection through affiliation with bystanders with whom they have a good relationship. Our study indicated that monkeys cope with post‐conflict problems according to their roles or situations not only by reconciliation but also by bystander affiliation.     

Effect of historical factors on genetic variation in three terrestrial Cephalanthera species (Orchidaceae) with different breeding system on the Korean Peninsula

Previous studies have shown that levels of genetic diversity in species of the genus Cephalanthera covary with the breeding system. In the southern part of the Korean Peninsula, the three self‐compatible terrestrial orchids Cephalanthera erecta, C. falcata and C. longibracteata flower synchronously in sympatric populations. The food‐deceptive C. falcata with bright yellow flowers is predominantly outcrossing, whereas autogamy is the dominant strategy in both C. erecta and C. longibracteata, whose white flowers do not open fully. We examined genetic diversity (by means of allozymes) of the three species in sympatric populations (600 × 600 m area) in the Yeonwhasan Provincial Park (YPP) and in non‐sympatric populations outside YPP, South Korea. Thirteen out of 20 putative loci were variable across the three species, but there was a complete lack of allozyme variation within each species and we found no evidence of hybridisation. Our results suggest that historical factors, i.e. the Quaternary climate oscillations, have played a major role in determining levels of genetic diversity in the three Cephalanthera species. The Korean populations of C. erecta (a warm‐temperate/temperate element) and C. falcata (a warm‐temperate element) may have been established by a single introduction from a genetically depauperate ancestral population, likely located outside the Korean Peninsula. On the other hand, since C. longibracteata is a boreal/temperate element, it may have survived the Last Glacial Maximum in microrefugia located in low elevation regions within the Peninsula where it has been subjected to population bottlenecks reducing its genetic diversity.     

Caspases and matrix metalloproteases facilitate collective behavior of non-neural ectoderm after hindbrain neuropore closure

Background

Mammalian brain is formed through neural tube closure (NTC), wherein both ridges of opposing neural folds are fused in the midline and remodeled in the roof plate of the neural tube and overlying non-neural ectodermal layer. Apoptosis is widely observed from the beginning of NTC at the neural ridges and is crucial for the proper progression of NTC, but its role after the closure remains less clear.

Results

Here, we conducted live-imaging analysis of the mid-hindbrain neuropore (MHNP) closure and revealed unexpected collective behavior of cells surrounding the MHNP. The cells first gathered to the closing point and subsequently relocated as if they were released from the point. Inhibition of caspases or matrix metalloproteases with chemical inhibitors impaired the cell relocation.

Conclusions

These lines of evidence suggest that apoptosis-mediated degradation of extracellular matrix might facilitate the final process of neuropore closure.

     

Preparation and Characterization of Monoclonal Antibodies Specific for Lauroylated Isoform of Bovine Transducin α-Subunit: Immunohistochemical Analysis of Bovine Retinas

Abstract: The photoreceptor G protein transducin [α- and βγ-subunits (Tα/Tβγ)] plays a central role in the visual transduction process. The amino-terminus of bovine Tα is modified by one of four distinct fatty acids—laurate (C12:0), myristate (C14:0), C14:1 (5- cis ), and C14:2 (5- cis , 8- cis )—but the biological significance and the localization of the four isoforms of Tα are poorly understood. To investigate the cellular distribution of each isoform, we prepared monoclonal antibodies against a synthetic C12:0-, C14:0-, C14:1-, or C14:2-nonapeptide corresponding to the N-terminal region of Tα. Among several types of antibodies isolated, only one type, represented by LA4, reacted specifically with the C12:0-peptide as well as purified Tα but not with the other proteins in bovine retinal homogenate, including recoverin, indicating that the epitope comprises both C12:0 and the N-terminal amino acids of Tα. Immunohistochemical analyses of bovine retinal sections by LA4 showed the uniform distribution of C12:0-Tα in almost all the rod outer segments. Hence, it seemed unlikely that each isoform of Tα was localized in specific cells. This observation, together with evidence for a possible functional diversity among the isoforms, suggests that the four isoforms of Tα in a single rod cell may contribute simultaneously to a fine tuning of the photon-signal transduction process.     

Comparison between wild-born mother-female infant interactions and laboratory-born mother-female infant interactions during the first 14 weeks after birth in individually caged cynomolgus macaques

In this study we compared mother-female infant interactions between primiparous and multiparous laboratory-born (F1) cynomolgus macaques (Macaca fascicularis) in individual cages at Tsukuba Primate Center (TPC), Japan, during the first 14 weeks of infant life. We also compared interactions between multiparousF1 mothers and their female infants with those between wild-born mothers and their female infants when mothers and their infants were housed in the same individual cages. PrimiparousF1 mothers showed significantly higher values for contact with and holding of their infants than multiparousF1 mothers. The primiparousF1 mothers also tended to behave aggressively toward their infants when the latter did not show any obviously irritating behaviors. Thus, the primiparousF1 mothers seemed to be inconsistent in terms of maternal behavior. Compared with multiparous wild-born mothers, multiparousF1 mothers moved more frequently, held their infants less frequently and acted aggressively toward their infants less frequently. However, infants ofF1 mothers, as well as infants of wild-born mothers, interacted with their mothers through approaching and playful contact with them. These findings indicate that the attitude of multiparousF1 mothers toward their infants was relatively passive. Possible reasons for the passive maternal style of multiparousF1 mothers are discussed.     

Excitation energy transfer in the green photosynthetic bacterium Chloroflexus aurantiacus: A specific effect of 1-hexanol on the optical properties of baseplate and energy transfer processes

The effect of 1-hexanol on spectral properties and the processes of energy transfer of the green gliding photosynthetic bacterium Chloroflexus aurantiacus was investigated with reference to the baseplate region. On addition of 1-hexanol to a cell suspension in a concentration of one-fourth saturation, a specific change in the baseplate region was induced: that is, a bleach of the 793-nm component, and an increase in absorption of the 813-nm component. This result was also confirmed by fluorescence spectra of whole cells and isolated chlorosomes. The processes of energy transfer were affected in the overall transfer efficiency but not kinetically, indicating that 1-hexanol suppressed the flux of energy flow from the baseplate to the B806-866 complexes in the cytoplasmic membranes. The fluorescence excitation spectrum suggests a specific site of interaction between bacteriochlorophyll (BChl) c with a maximum at 771 nm in the rod elements and BChl a with a maximum at 793 nm in the baseplate, which is a funnel for a fast transfer of energy to the B806-866 complexes in the membranes. The absorption spectrum of chlorosomes was resolved to components consistently on the basis, including circular dichroism and magnetic circular dichroism spectra; besides two major BChl c forms, bands corresponding to tetramer, dimer, and monomer were also discernible, which are supposed to be intermediary components for a higher order structure. A tentative model for the antenna system of C. aurantiacus is proposed.Abbreviations A670 a component whose absorption maximum is located at 670 nm - (B)Chl (bacterio)chlorophyll - CD circular dichroism - F675 a component whose emission maximum is located at 675 nm - FMO protein Fenna-Mathews-Olson protein - LD linear dichroism - LH light-harvesting - McD magnetic circular dichroism - PS photosystem - RC reaction center     

OlpB, a new outer layer protein of Clostridium thermocellum, and binding of its S-layer-like domains to components of the cell envelope.

Several proteins of Clostridium thermocellum possess a C-terminal triplicated sequence related to bacterial cell surface proteins. This sequence was named the SLH domain (for S-layer homology), and it was proposed that it might serve to anchor proteins to the cell surface (A. Lupas, H. Engelhardt, J. Peters, U. Santarius, S. Volker, and W. Baumeister, J. Bacteriol. 176:1224-1233, 1994). This hypothesis was investigated by using the SLH-containing protein ORF1p from C. thermocellum as a model. Subcellular fractionation, immunoblotting, and electron microscopy of immunocytochemically labeled cells indicated that ORF1p was located on the surface of C. thermocellum. To detect C. thermocellum components interacting with the SLH domains of ORF1p, a probe was constructed by grafting these domains on the C terminus of the MalE protein of Escherichia coli. The SLH domains conferred on the chimeric protein (MalE-ORF1p-C) the ability to bind noncovalently to the peptidoglycan of C. thermocellum. In addition, 125I-labeled MalE-ORF1p-C was shown to bind to SLH-bearing proteins transferred onto nitrocellulose, and to a 26- to 28-kDa component of the cell envelope. These results agree with the hypothesis that SLH domains contribute to the binding of exocellular proteins to the cell surface of bacteria. The gene carrying ORF1 and its product, ORF1p, are renamed olpB and OlpB (for outer layer protein B), respectively.