Comparative genome sequence analysis of the Bpa/Str region in mouse and man

The progress of human and mouse genome sequencing programs presages the possibility of systematic cross-species comparison of the two genomes as a powerful tool for gene and regulatory element identification. As the opportunities to perform comparative sequence analysis emerge, it is important to develop parameters for such analyses and to examine the outcomes of cross-species comparison. Our analysis used gene prediction and a database search of 430 kb of genomic sequence covering the Bpa/Str region of the mouse X chromosome, and 745 kb of genomic sequence from the homologous human X chromosome region. We identified 11 genes in mouse and 13 genes and two pseudogenes in human. In addition, we compared the mouse and human sequences using pairwise alignment and searches for evolutionary conserved regions (ECRs) exceeding a defined threshold of sequence identity. This approach aided the identification of at least four further putative conserved genes in the region. Comparative sequencing revealed that this region is a mosaic in evolutionary terms, with considerably more rearrangement between the two species than realized previously from comparative mapping studies. Suprisingly, this region showed an extremely high LINE and low SINE content, low G+C content, and yet a relatively high gene density, in contrast to the low gene density usually associated with such regions

Adult fecundity, host plant preferences, field activity and parasitism in the leaf weevil Phyllobius pyri (L.) (Coleoptera: Curculionidae)

Adults of the leaf weevil Phyllobius pyri (L.) (Coleoptera: Curculionidae) feed on a wide variety of broadleaved trees and occasionally cause severe defoliation in newly established farm woodlands. There is little information, however, on the relative susceptibility of different tree species to damage or on the habitat associations of adults and larvae of P. pyri, which might indicate the conditions that predispose trees to attack. Captures of adult P. pyri in emergence and flight traps in the current study indicated population densities in grassland of 0.5-6.4 adults per m(2) at emergence but higher densities up to 13.5 per m(2) in young pine plantations, where there was a mixture of grassy patches and young, naturally regenerating birch trees. The close proximity of larval food resources (grass roots) and a favoured adult host-plant, which also occurs in young farm woodlands, provided ideal conditions for P. pyri and allowed high population densities to develop. Feeding and performance experiments indicated that cherry, birch, oak and hornbeam were most susceptible to P. pyri, whereas field maple, hawthorn, rowan, lime and especially ash were resistant. Adult female P. pyri emerged in May reproductively immature and fed on tree foliage for 15.9 +/- 0.9 days before laying their first batch of eggs. Adults lived for 33.3 +/- 1.5 days, on average, and females laid a mean of 191.9 +/- 34.5 eggs (maximum = 589) during their lifetime. Eggs hatched after 16-20 days. During 2003 and 2004, 11-16% of adult P. pyri were parasitised by Pygostylus falcatus (Hymenoptera: Braconidae) and 19-29% were parasitised by Rondonia fasciata (Diptera: Tachinidae)