Introduced house mice as a conservation concern on Gough Island

House mice have previously been identified as a significant threat to both species and ecosystems on Southern Ocean islands. To date, these impacts have been quantified on several sub-Antarctic islands, but the role of house mice on more temperate islands is poorly known. On South Atlantic Gough Island, non-commensal house mice (Mus musculus L.) were probably introduced in the early 19th century and are now extremely abundant. To assess the likely impacts of mice on the fauna and flora at Gough Island we examined the diet of this population from September 1999 to July 2000 using conventional snap trapping techniques. The population has a single breeding season from September to March and mean body mass is notable in being amongst the largest reported for non-laboratory M. musculus. At low elevations (<250 m above sea level [a.s.l.]), avian carrion was the most prevalent dietary item during September and October. From November to February, plant material constituted the bulk of stomach contents and from March to July lumbricid worms were the most common food item. Indigenous invertebrate matter contributed little to mouse diet, independent of season. At altitudes greater than 500 m a.s.l., larvae of endemic brachypterous moths made up a significant proportion of stomach contents. In light of studies elsewhere, these data suggest that mouse predation may pose a significant threat to these species. However, it is not clear whether conservation action, such as an eradication attempt, is warranted. Further assessments of the impacts of mice are required, and in the interim every effort should be made to prevent introductions of other potentially harmful invasive species.     

Linkage relationships of peptidase-7, Pep-7, in the mouse

An electrophoretically detectable variant of peptidase-7 in Mus musculus has been found and used to locate the structural gene, Pep-7, on chromosome 5. Gene order and recombination frequencies are estimated as Pep-7 3.5±2.0 Rw 8.8±2.2 go 20.0±4.6 bf.     

The distribution and relative potency of diuretic peptides in the house cricket, Acheta domesticus

ABSTRACT Dose-response curves are presented for the diuretic activity in aqueous extracts of brain, retrocerebral complex, and ventral nerve cord ganglia from Acheta domesticus . Diuretic activity is highest in extracts of brain and corpora cardiaca. In comparison with such extracts, those of the suboesophageal ganglia and thoracic ganglia I-III produce truncated responses, whilst abdominal ganglia 1–4 show evidence of an inhibition of the diuretic response at high doses. ED₅₀ values, obtained from Hill plots, are similar for extracts of brain, corpora cardiaca, corpora allata, and abdominal ganglia, but are 3–4 times higher for extracts of suboesophageal and thoracic ganglia.
Separation of aqueous extracts of corpora cardiaca by reversed-phase HPLC yields a number of fractions which stimulate fluid secretion in isolated tubules. Diuretic activity in these fractions is destroyed by treatment with Pronase E, and on this basis is identified as peptidic. In general, diuretic activity is found in the same RP-HPLC fractions prepared from aqueous extracts of brain, suboesophageal ganglia, thoracic ganglia I-III, and abdominal ganglia 1–4.