Adenovirus serotype determines association and localization of the large E1B tumor antigen with cellular tumor antigen p53 in transformed cells.

The distribution and stability of the cellular tumor antigen p53 were studied in baby rat kidney cells transformed by region E1 sequences of nononcogenic adenovirus (Ad) type 5 (Ad5) or oncogenic type 12 (Ad12). In transformed cells expressing the large E1B T antigen of Ad5, p53 was associated with this T antigen. The complexed proteins were concentrated in a cytoplasmic body, which has been shown to consist of a cluster of 8-nm filaments (A. Zantema et al., Virology 142:44-58, 1985). In transformed cells expressing the E1B region of Ad12, however, no association between the viral large T antigen and p53 was detectable. In the latter case, both proteins were found almost exclusively in the nucleus. The stability of p53 in both Ad5- and Ad12-transformed cells was increased relative to that in primary cells or cells immortalized by the E1A region only. Thus, the increased stability of p53 in Ad-transformed cells is not caused by association with a viral T antigen, but it correlates with expression of E1B and with morphological transformation.     

The accessory olfactory system and its role in the pheromonally mediated suppression of oestrus in grouped mice

Mice were grouped to induce suppression of oestrus and subjected to removal of the vomeronasal organs or treatment with CB 154 which lowers prolactin levels. Both treatments overcame the suppression of oestrus after 72 h. Oestrus suppression was induced in lesioned mice by haloperidol treatment which raises plasma prolactin, and oestrus returned some 72 h after withdrawal of haloperidol treatment.     

Pheromones, vomeronasal function, and gender-specific behavior

The striking behavioral phenotypes of mice lacking the TRP2 ion channel have highlighted the importance of the vomeronasal organ in gender-specific sexual behavior.     

The disparate maternal aunt-uncle ratio in male transsexuals: an explanation invoking genomic imprinting

A significant skewing in the sex ratio in favour of females has been reported for the families of homosexual men such that there are fewer maternal uncles than aunts. This finding is repeated for a large series of transsexual families in this study. Four hundred and seventeen male-to-female transsexuals and 96 female-to-male transsexuals were assessed. Male-to-female transsexuals have a significant excess of maternal aunts vs. uncles. No differences from the expected parity were found for female-to-male transsexuals or on the paternal side. A posited explanation for these findings invokes X inactivation and genes on the X chromosome that escape inactivation but may be imprinted. Our hypothesis incorporates the known familial traits in the families of homosexuals and transsexuals by way of retention of the grand parental epigenotype on the X chromosome. Generation one would be characterized by a failure to erase the paternal imprints on the paternal X chromosome. Daughters of this second generation would produce sons that are XpY and XmY. Since XpY expresses Xist, the X chromosome is silenced and half of the sons are lost at the earliest stages of pregnancy because of the normal requirement for paternal X expression in extra-embryonic tissues. Females survive by virtue of inheriting two X chromosomes, and therefore the possibility of X chromosome counting and choice during embryonic development. In generation three, sons inheriting the paternal X after its second passage through the female germline survive, but half would inherit the feminizing Xp imprinted genes. These genes could pre-dispose the sons to feminization and subsequent development of either homosexuality or transsexualism.     

STING Millennium Suite: integrated software for extensive analyses of 3d structures of proteins and their complexes

Background  

The integration of many aspects of protein/DNA structure analysis is an important requirement for software products in general area of structural bioinformatics. In fact, there are too few software packages on the internet which can be described as successful in this respect. We might say that what is still missing is publicly available, web based software for interactive analysis of the sequence/structure/function of proteins and their complexes with DNA and ligands. Some of existing software packages do have certain level of integration and do offer analysis of several structure related parameters, however not to the extent generally demanded by a user.     

DETECTION AND ENUMERATION OF H2S+ BACTERIA: APPLICATION TO SHEWANELLA PUTREFACIENS (CIP)

H₂S⁺ bacteria responsible for the degradation of sulfur-containing amino acids of fish muscle are currently little used to evaluate the microbiological pal quality of fish. Shewanella putrefaciens greatly predominates in this flora, and was therefore used to define a suitable culture method and medium. Inoculations by the Spiral surface method at 25C, with an incubation of 72h, gave the best counts on a medium containing two sources of sulfur (organic and inorganic) for H₂S⁺ bacteria. The culture medium and the NaCl concentration were determinant in the evaluation of this flora. At present there is no standard medium which meets these requirements.     

Sex difference in attraction thresholds for volatile odors from male and estrous female mouse urine

Volatile urinary odors from opposite sex conspecifics contribute to mate recognition in numerous mammalian species, including mice. We used a simple habituation/dishabituation testing procedure to ask whether the capacity to detect and investigate decreasing concentrations of volatile urinary odors is sexually differentiated in mice. Beginning 2 months after gonadectomy and in the absence of any sex steroid treatment, adult, sexually naive male and female CBA x C57Bl/6 F1 hybrid mice received two series of daily tests that involved the presentation of different dilutions of urine from C57Bl/6 males followed by urine from estrous females. Each test session began with three consecutive presentations of deionized water (10 microl on filter paper for 2 min, behind a mesh barrier which prevented direct physical access, in the home cage at 1-min intervals) followed by three presentations of one of five different dilutions of urine (a different dilution on each test day). Males and females showed equivalent, significant habituation/dishabituation responses (low investigation times for successive water presentations; increased investigation of the first urine stimulus, followed by a decline in successive urine investigation times) to both male and female urine/water dilutions of 1:1, 1:10, and 1:20. However, only female mice responded reliably to 1:40 and 1:80 dilutions of both types of urine, pointing to a sex dimorphism in the detection and/or processing of biologically relevant, volatile urinary odors by the main olfactory system.     

Suppression of prolactin does not reduce infant care by parentally experienced male common marmosets (Callithrix jacchus)

High levels of prolactin have been found to correlate with the expression of paternal care in a variety of taxa. However, in mammals, there is little experimental evidence that prolactin is causally involved in the stimulation or maintenance of paternal care. Here, we suppressed prolactin production in paternally experienced common marmoset fathers in their family groups during the first 2 weeks after their infants were born. Circulating prolactin levels were suppressed using cabergoline (Dostinex: Pfizer), a long acting dopamine (D2) agonist with minimal behavioural side-effects. A within-subject design was used to compare behavioural and hormonal data on 5 paternally experienced fathers during two consecutive births. Cabergoline reduced prolactin to negligible levels in all fathers without effecting testosterone, DHT and cortisol and without adverse side-effects. However, lowering prolactin had no significant effect on the expression of majority of the behaviour patterns associated with paternal care. These included infant carrying, infant grooming and the frequency with which fathers retrieved and rejected infants. The only infant-related behaviour to be affected was the frequency with which fathers touched, licked and investigated infants. We noted a marginally significant increase in this behaviour during cabergoline treatment. Despite the lack of effect on paternal care, cabergoline did exert an effect on the affiliative/sexual behaviour of fathers as there was a significant increase in the grooming behaviour fathers directed at and received from their mates during drug treatment. This study showed that experienced male marmosets can express paternal behaviour in the absence of the high prolactin levels normally seen after infants are born.     

Mammalian pheromones: from genes to behaviour

Knocking-out selected genes for receptors of the vomeronasal organ has been found to impair specific aspects of pheromone-induced behaviour in the mouse. This is not unexpected; less predictable is the finding that deleting the gene for a vomeronasal-organ-specific ion channel causes gender blindness.