Germ Cell Nuclear Factor: An Orphan Receptor in Search of a Function

Germ Cell Nuclear Factor (GCNF) is an orphan member of the nuclearreceptor gene superfamily. Much has been understood about thefunctioning of GCNF which represents a candidate receptor fora novel hormonal signalling pathway. GCNF is not closely relatedto other members of the nuclear receptor superfamily and formsits own branch within the superfamily tree. It has a uniqueexpression pattern that spans both embryonic and adult stagesof development. In the adult, it is expressed in the germ cells:oocytes and spermatogenic cells as well as specific neuronalcells within the brain. In the embryo, GCNF expression is turnedon after gastrulation in all germ layers the ectoderm, mesodermand endoderm. An antero-posterior gradient of GCNF is establishedin the neuroectoderm of the embryo, suggesting a role in regulationof neuronal and germ cell development. Regulation of physiologicalprocesses by a nuclear receptor is achieved through regulationof gene expression. GCNF is the only nuclear receptor to specifcallybind to DR0 hormone response elements to regulate gene expression.In the absense of a ligand, GCNF represses gene expression.GCNF is capable of regulating the expression of the protaminegenes in a response element-dependent manner. At present theligand for GCNF is unknown, but it is hypothesized that GCNFis a receptor for a novel hormonal signalling pathway that effectsits biological response by regulating the expression of a subsetof genes containing DR0 response elements.     

THE EFFECT OF COMMERCIAL TRAPPING ON RABBIT POPULATIONS

The effect of commercial trapping on two rabbit populations in West Wales, was investigated during 1946 to 1949. On two farms rabbits were caught alive in snares, marked and released just before trapping; the total number of rabbits marked, divided by the fraction of marked rabbits recovered in the trapped sample gave an estimate of the population before trapping started. Trapping usually removed 30–40 % of the rabbits present, a proportion compatible with a careful cropping of the population. At one farm, studied for 3 years, the population increased steadily.
Breeding was intense from January to June inclusive, and from weight and age distributions it was apparent that in 1948 and 1949 considerable breeding also occurred in autumn. The sex ratio varied around a mean of about 50%.
Data are given on movements, obtained from recapture records of zog marked animals. They suggest that rabbits probably forage over an area of not more than 150 yards in diameter. The records from recaptured marked animals indicate that the mean expectation of life is about 6 months.     

Fence-Line Contact Between Wild and Farmed Cervids in Colorado: Potential for Disease Transmission

Abstract: Direct and indirect contact between wild and farmed cervids along perimeter fences may play a role in transmission of diseases like chronic wasting disease (CWD), but no studies have quantified such interactions. At 9 high-fenced commercial elk (Cervus elaphus) farms in Colorado, USA, during October 2003 to January 2005, we used animal-activated video to estimate rates of fence-line use by wild cervids, rates of direct contact between farmed and wild cervids, and probability of direct contact when wild cervids were present. We recorded 8-fold-more wild elk per unit time than mule deer (Odocoileus hemionus) at fence lines. Depending on site, we recorded 0.66 to 46.90 wild elk per 1,000 hours of camera monitoring. We documented 77 interactions between wild and farmed elk involving naso-oral contact and no contact between wild mule deer and farmed elk. Rate of direct contact ranged from 0.00 to 1.92 direct contacts per 1,000 hours of camera monitoring among sites. Given recorded presence of wild elk, estimated probability of observing direct contact during a 2-minute video recording ranged from 0.00 to 0.11 among sites. Risk of direct contact was about 3.5 times greater for single woven-wire fence compared with offset electric fence attached to a single woven-wire fence. We observed no direct contact through double woven-wire fences. Because little is currently known about infection rates associated with infection mechanisms, we cannot infer a level of CWD infection risk from our results, but some form of double fencing should reduce potential for direct and indirect transmission of disease into or out of elk farms.     

The breeding biology of White-tailed Tropicbirds Phaethon lepturus at Cousin Island, Seychelles

During 1981–1983 the population of White-tailed Tropicbirds Phaethon lepturus at Cousin Island, Seychelles, bred aseasonally and asynchronously. The mean interval between consecutive successful breeding attempts was 273 days. Most individuals nested in the same site, and with the same partner, in successive attempts, but 7-5% of nest sites were used by more than one pair; 21 % of pairs which lost eggs, and 13% of those which lost chicks re-nested. Incubation lasted 40–41 days, with a mean incubation shift length of 6-6 days. Fledging periods varied between 67 and 89 days (mean 76-5 days). Mean fledging weight was not significantly greater than the average weight of breeding adults.
Fledging success was 36%. Many of the 39% of eggs which failed to hatch probably did so as a result of exposure to the sun's heat, following temporary desertion by adults which were themselves heat-stressed during incubation. Of the 41 % of chicks which died, most died young; many were probably killed by crabs Ocypode spp. Not more than 10% of all nest failures were due to nest site competition. A few chicks probably starved to death.
At the time of the study, both food and nesting sites were evidently in excess. A considerable increase in the size of the population will be possible before density-dependent control mechanisms begin to operate.     

Evaluation of fine needle aspiration of the male breast for the diagnosis of gynaecomastia

Fine needle aspiration of the male breast can present problems of diagnosis because the cytological presentation of gynaecomastia can be confused with that of adenocarcinoma. We reviewed breast aspirates from 24 male patients in order to determine the accuracy of cytology as a method of diagnosing gynaecomastia. Discrepancies were observed between the original cytology reports on one hand and the review cytology and biopsies on the other. Of the 24 aspirates from the male breast, the cytology was reported as negative in 16 cases, suspicious in three cases and malignant in five. In four cases of the negative group, a specific diagnosis of gynaecomastia was made. In two of the negative cases the subsequent biopsies revealed adenocarcinoma. Of the five cases reported on the original cytology as adenocarcinoma, two on review showed the features of florid gynaecomastia and this was confirmed on biopsy and three confirmed the initial diagnosis of adenocarcinoma. The cytological features of gynaecomastia which distinguish it from adenocarcinoma are discussed.     

A sporulation medium for Clostridium perfringens

A new solidified medium for inducing sporulation of Clostridium perfringens is described. The essential components of the medium are bile, bicarbonate and quinoline. The medium induced significant sporulation in all of 100 strains of Cl. perfringens isolated at random from human faecal specimens. The majority (94%) of strains sporulated profusely.     

Synthesis of Substance P

SUBSTANCE P has been synthesized by the solid-phase procedure of Merrifield^1,2 according to the sequence H-Arg-Pro-LysPro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH₂ reported in the previous letter.     

Passive Haemagglutination Test for Anti-rhinovirus Antibodies

The use of chromic chloride as a coupling reagent has made it possible to coat red cells with rhinovirus protein. This is shown by immunofluorescence, electron microscopy and immunocolloidal experiments.     

Cell-free Studies on the Regulation of the Arabinose Operon

A DNA directed, cell-free system which synthesized L-ribulokinase coded by the L-arabinose operon ara OIBAD, has been developed. L-arabinose but not the araC gene product is required for the expression of this operon and, in addition, cyclic AMP and guanosine tetraphosphate are needed for optimal synthesis.