Genotype/age interactions on aggressive behavior in gonadally intact estrogen receptor beta knockout (betaERKO) male mice

Estrogen, as an aromatized metabolite of testosterone, has a facilitatory effect on male aggressive behavior in mice. Two subtypes of estrogen receptors, alpha (ER-alpha) and beta (ER-beta), in the brain are known to bind estrogen. Previous studies revealed that the lack of ER-alpha gene severely reduced the induction of male aggressive behavior. In contrast, mice that lacked the ER-beta gene tended to be more aggressive than wild type (WT) control mice, although the behavioral effects of ER-beta gene disruption were dependent on their social experience. These findings lead us to hypothesize that estrogen may facilitate aggression via ER-alpha whereas it may inhibit aggression via ER-beta. In the present study, we further investigated the role of ER-beta in the regulation of aggressive behavior by examining developmental changes starting at the time of first onset, around the age of puberty. Aggressive behaviors of ER-beta gene knockout (betaERKO) mice were examined in three different age groups, puberty, young-adult, and adult. Each mouse was tested every other day for three times in a resident-intruder paradigm against olfactory bulbectomized intruder mice and their trunk blood was collected for measurements of serum testosterone after the completion of the study. Overall, betaERKO mice were significantly more aggressive than WT. These genotype differences were more pronounced in puberty and young adult age groups, but not apparent in the adult age group, in which betaERKO mice were less aggressive than those in two younger age groups. Serum testosterone levels of betaERKO mice were significantly higher than those of WT mice only in the pubertal age group, but not in young adult (when betaERKO mice were still significantly more aggressive than WT mice) and adult (when no genotype differences in aggression were found) age groups. These results suggest that ER-beta mediated actions of gonadal steroids may more profoundly be involved in the inhibitory regulation of aggressive behavior in pubertal and young adult mice.     

Litter Nutrient Dynamics During Succession in Dry Tropical Forests of the Yucatan: Regional and Seasonal Effects

Land-use change in the tropics is creating secondary forest at an unprecedented rate. In the tropical Americas, mature dry tropical forest is rapidly being converted to secondary forest during the fallow period of shifting cultivation. We investigated litter phosphorus (P) and nitrogen (N) dynamics in forests recovering from shifting cultivation of maize (corn) in three regions of the Southern Yucatan Peninsula, Mexico. Our goal was to understand how nutrient and water availability affect forest recovery following conversion of mature forest to agricultural land. To investigate such changes at a regional scale, newly fallen litter was collected monthly along a seasonal, a successional, and a precipitation gradient. Reflecting possible P limitation, litter P concentration declined with forest age, while litter N concentration did not differ between age classes. Average litter P concentration from the southern, wettest region was 0.87 mg/g, almost twice the litter P concentration in the drier central and northern regions (0.44 and 0.45 mg/g, respectively). Average N concentrations of litter from the three regions ranged from 1.1% to 1.2%, with no regional differences. However, minima in both P and N concentration from all regions were pronouncedly timed with peak litterfall, suggesting nutrient retranslocation during periods of water stress. Additionally, successional differences in litter P were clearest during wetter months. P nutrient-use efficiency was lowest in the southern region and highest in the central and northern study regions. N nutrient-use efficiency was up to 40 times lower than P nutrient-use efficiency and showed no regional differences. Overall, our results suggest that litter nutrient dynamics in secondary dry tropical forests of the Southern Yucatan are strongly influenced by water and nutrient availability, especially P, as well as land-use history.     

Overexpression of juvenile hormone binding protein in bacteria and Pichia pastoris

Galleria mellonella juvenile hormone binding protein (JHBP) is a single chain glycoprotein with two disulfide bonds and a molecular mass of 25,880 Da. This report describes the expression of JHBP in bacteria and yeast cells (Pichia pastoris). The expression in bacteria was low and the protein was rapidly degraded upon cell lysis. The expression of His8-tagged rJHBP (His8-rJHBP) in P. pastoris was high and the non-degraded protein was purified to homogeneity with high yield in a one-step immobilized Ni++ affinity chromatography. His8-rJHBP from P. pastoris contains one JH III binding site with KD of 3.7 +/- 1.3x10(-7) M. The results suggest that P. pastoris is the preferred system for expression of His8-rJHBP in non-degraded fully active form.     

Reinvestigation of the <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> genome annotation by comparison to the genome of a related fungus: <Emphasis Type="Italic">Ashbya gossypii</Emphasis>

Background  

The recently sequenced genome of the filamentous fungus Ashbya gossypii revealed remarkable similarities to that of the budding yeast Saccharomyces cerevisiae both at the level of homology and synteny (conservation of gene order). Thus, it became possible to reinvestigate the S. cerevisiae genome in the syntenic regions leading to an improved annotation.     

Titin: properties and family relationships

In striated muscles, the rapid production of macroscopic levels of force and displacement stems directly from highly ordered and hierarchical protein organization, with the sarcomere as the elemental contractile unit. There is now a wealth of evidence indicating that the giant elastic protein titin has important roles in controlling the structure and extensibility of vertebrate muscle sarcomeres.     

Infant mortality after takeovers in wild Ethiopian hamadryas baboons

In this work we report the first observational evidence of infanticide in wild hamadryas baboons. The study group inhabits the lowlands of the northern Rift Valley in Ethiopia and has been under observation for over 1,200 hr, on and off, since October 1996. Here we report observations from August and September 2002 of the consequences of two takeovers of known females with black infants. After the first takeover, the respective infant disappeared and was presumed dead within 11 days of the takeover. After the second takeover, the infant incurred repeated severe aggression from its mother's new leader male and eventually died 4 days after the takeover. We interpret these findings as support for the sexual selection hypothesis regarding male infanticide. We suggest that hamadryas leader males usually protect infants born into their units, but may withhold this protection-or even directly attack and kill infants-after takeovers.     

Association Between the Rat Homologue of CO-029, a Metastasis-associated Tetraspanin Molecule and Consumption Coagulopathy

Recently, we have described a panel of metastasis-associated antigens in the rat, i.e., of molecules expressed on metastasizing, but not on nonmetastasizing tumor lines. One of these molecules, recognized by the monoclonal antibody D6.1 and named accordingly D6.1A, was found to be abundantly expressed predominantly on mesenchyme-derived cells. The DNA of the antigen has been isolated and cloned. Surprisingly, the gene product proved to interfere strongly with coagulation.

The 1.182-kb cDNA codes for a 235–amino acid long molecule with a 74.2% homology in the nucleotide and a 70% homology in the amino acid sequence to CO-029, a human tumor-associated molecule. According to the distribution of hydrophobic and hydrophilic amino acids, D6.1A belongs to the tetraspanin superfamily. Western blotting of D6.1A-positive metastasizing tumor lines revealed that the D6.1A, like many tetraspanin molecules, is linked to further membrane molecules, one of which could be identified as α6β1 integrin. Transfection of a low-metastasizing tumor cell line with D6.1A cDNA resulted in increased metastatic potential and provided a clue as to the functional role of D6.1A. We noted massive bleeding around the metastases and, possibly as a consequence, local infarctions predominantly in the mesenteric region and all signs of a consumption coagulopathy. By application of the D6.1 antibody the coagulopathy was counterregulated, though not prevented.

It has been known for many years that tumor growth and progression is frequently accompanied by thrombotic disorders. Our data suggest that the phenomenon could well be associated with the expression of tetraspanin molecules.

     

The fourth level of social structure in a multi‐level society: ecological and social functions of clans in hamadryas baboons

Hamadryas baboons are known for their complex, multi‐level social structure consisting of troops, bands, and one‐male units (OMUs) [Kummer, 1968. Social organization of hamadryas baboons. Chicago: The University of Chicago Press. 189p]. Abegglen [1984. On socialization in hamadryas baboons: a field study. Lewisburg, PA: Bucknell University Press. 207p.] observed a fourth level of social structure comprising several OMUs that rested near one another on sleeping cliffs, traveled most closely together during daily foraging, and sometimes traveled as subgroups independently from the rest of the band. Abegglen called these associations “clans” and suggested that they consisted of related males. Here we confirm the existence of clans in a second wild hamadryas population, a band of about 200 baboons at the Filoha site in lowland Ethiopia. During all‐day follows from December 1997 through September 1998 and March 2005 through February 2006, data were collected on activity patterns, social interactions, nearest neighbors, band fissions, and takeovers. Association indices were computed for each dyad of leader males, and results of cluster analyses indicated that in each of the two observation periods this band comprised two large clans ranging in size from 7 to 13 OMUs. All band fissions occurred along clan lines, and most takeovers involved the transfer of females within the same clan. Our results support the notion that clans provide an additional level of flexibility to deal with the sparse distribution of resources in hamadryas habitats. The large clan sizes at Filoha may simply be the largest size that the band can split into and still obtain enough food during periods of food scarcity. Our results also suggest that both male and female relationships play a role in the social cohesion of clans and that males exchange females within clans but not between them. Am. J. Primatol. 71:948–955, 2009. © 2009 Wiley‐Liss, Inc.     

High SEPT9_i1 Protein Expression Is Associated with High-Grade Prostate Cancers

Septins are a family of GTP-binding cytoskeleton proteins expressed in many solid tumors. Septin 9 (SEPT9) in particular was found overexpressed in diverse carcinomas. Herein, we studied the expression of SEPT9 isoform 1 protein (SEPT9_i1) in human prostate cancer specimens. We utilized immunohistochemical staining to study the expression of SEPT9_i1 protein. Staining level was analyzed in association with clinical characteristics and the pathological Gleason grade and score. Fifty human prostate cancer specimens (42 primary tumors and 8 metastatic lesions) were stained by SEPT9_i1 antibody and analyzed. SEPT9_i1 protein was expressed in prostate cancer cells but absent in normal epithelial cells. The intensity of staining was correlated proportionally to pretreatment prostate-specific antigen (PSA) blood levels and Gleason score (P < 0.05). SEPT9_i1 was highly expressed in all metastatic lesions. A significant assocation between SEPT9_i1 expression and high Gleason score on multivariate linear regression analysis was found. We conclude that SEPT9_i1 is expressed in high-grade prostate tumors suggesting it has a significant role in prostate tumorigenesis and that it could serve as a molecular marker for prostate tumor progression.