A rapid PCR-based test for the endogenous viral element ev3 of chickens

A short fragment of chicken genomic DNA encompassing the insertion site of the endogenous avian leucosis viral element ev 3 was isolated using the inverse polymerase chain reaction (inverse PCR) technique. The nucleotide sequence of the unoccupied site was used to design PCR primers that can be used to unambiguously determine the genetic status of any chicken, with respect to ev 3. Screening of a small number of individuals from exotic breeds of chickens suggested that the frequency of ev 3 is highly variable. The ev 3 integration site shows a high degree of sequence homology with the macrophage-specific tyrosine kinase gene, bmk , in mice.     

Interactions of Muscarinic Receptors with the Heterotrimeric G Proteins Gq and G12: Transduction of Proliferative Signals

Abstract: The proliferative and transforming properties of m2 and m5 muscarinic acetylcholine receptors and a series of wild-type, chimeric, and mutant G proteins were measured alone or in combination in NIH 3T3 cells to determine which G proteins mediate these signals and to what extent these signals can be influenced by changing the stoichiometry of receptors and G proteins. Responses were measured using the focus-forming assay and a novel assay called R-SAT (R eceptor S election and A mplification T echnology) in which proliferative responses are monitored using a reporter gene. Individually, GTPase-deficient mutants (^?) of Gαq and Gα12, wild-type Gαq, and m5 were active in R-SAT. Gα12^? and m5 also induced focus formation. m2 was inactive in both assays. The ability of m5 to induce foci was significantly reduced by coexpression of Gαq^?. Synergistic effects of receptor/G protein combinations were not observed in focus-forming assays but were readily detected by R-SAT. Coexpression of Gαq with m5 induced constitutive activity in R-SAT and increased the potency of agonists at m5 by 90-fold. Gαq also evoked agonist-dependent responses from m2 but not constitutive activity. Agonist potency was increased 10-fold at m2 and decreased 15-fold at m5 when these receptors were coexpressed with Gαqi5, a chimeric G protein containing the five C-terminal residues of Gαi2, compared with coexpression with Gαq. Both Gαq and Gαqi5 had biphasic effects on the proliferative responses to m5 and m2, respectively, inhibiting responses at high agonist concentrations. Coexpression of Gα12 or Gα12i5 had no effect on the concentration-response relationships of m5, but both elicited weak responses from m2. We conclude that although Gα12 is a more potent oncogene, Gαq transduces m5-driven cellular responses. The demonstrations that proliferative responses can be elicited from a nonmitogenic receptor by altering the type and concentration of available G proteins and that constitutive responses can be induced by G proteins imply that both the magnitude and type of receptor-initiated signal can be regulated at the level of G proteins in vivo.     

Attractive men induce testosterone and cortisol release in women

Recently, Roney et al. (Roney, J.R., Lukaszewski, A.W., Simmons, Z.L., 2007. Rapid endocrine responses of young men to social interactions with young women. Horm. Behav. 52, 326-33; Roney, J.R., Mahler, S.V., Maestripieri, D., 2003. Behavioral and hormonal responses of men to brief interactions with women. Evol. Hum. Behav. 24, 365-375) demonstrated that men release testosterone and cortisol in response to brief social interactions with young women. The current experiment examined whether women show a similar endocrine response to physically and behaviorally attractive men. 120 women (70 naturally-cycling and 50 using hormonal contraceptives) were shown one of four 20-minute video montages extracted from popular films, depicting the following scenarios: 1) an attractive man courting a young woman (experimental stimulus), 2) a nature documentary (video clip control), 3) an unattractive older man courting a woman (male control), and 4) an attractive woman with no men present (female control). Saliva samples were taken before and after presentation of the stimulus, and were later analyzed for testosterone and cortisol content via enzyme immunoassay. Naturally-cycling women experienced a significant increase in both testosterone and cortisol in response to the experimental stimulus but to none of the control stimuli. Participants taking hormonal contraceptives also showed a significant cortisol response to the attractive man. Women may release adrenal steroid hormones to facilitate courtship interactions with high mate-value men.     

The value of figs to chimpanzees

Nine Ugandan figs have consistent differences in nutrient concentration between the pulp and seed fractions. Pulp has more water-soluble carbohydrates, complex carbohydrates, calories, and ash, while the seed fraction has more condensed tannins, lipids, and fiber. Because species differ, nutrient concentration in pulp could not be predicted from analysis of whole figs. Chimpanzees in Kibale Forest relied heavily on figs throughout 29 months, feeding relatively intensely at large trees. Fig size varied between species, between individuals of the same species, and between fruiting cycles of the same tree. Larger figs had higher water concentrations but still led to higher rates of nutrient intake per minute for chimpanzees, monkeys, and hornbills. Chimpanzees ate more than 40 cal/min, excluding calories derived from insoluble fiber, when harvesting large figs.Deceased, July 1990.