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41.
Gene regulatory divergence among species estimated by altered developmental patterns in interspecific hybrids 总被引:4,自引:0,他引:4
Disturbances in the schedules of gene expression in developing
interspecific fish hybrids have been used to draw inferences about the
extent of gene regulatory divergence between species and about the degree
to which this gene regulatory divergence is correlated with structural gene
divergence, as estimated by genetic distance. Sperm from each of 10
different species representing six genera within the family Centrarchidae
was used to fertilize eggs of the Florida largemouth bass (Micropterus
salmoides floridanus). The genetic distances (D; Nei 1978) between the
parental species used to form the hybrids ranged from 0.133 to 0.974. The
developmental success and temporal patterns of gene expression of each of
the hybrids were compared with those of the Florida largemouth bass. As the
genetic distance between the paternal species and the Florida largemouth
bass increased, there was a general decline in developmental success in the
hybrid embryos as demonstrated by the observed reductions in the percentage
of hatching and by progressively earlier and more extensive morphological
abnormalities. Concomitantly, progressively more marked alterations in
developmental schedules of expression of 15 enzyme loci occurred in the
hybrids as the genetic distance between parental species increased.
However, observed deviations from this trend for a few species may
represent an uncoupling of the rates and modes of evolution of structural
genes from those for genes regulating developmental processes.
相似文献
42.
Alexander Walz Cesar V Mujer Joseph P Connolly Tim Alefantis Ryan Chafin Clarissa Dake Jessica Whittington Srikanta P Kumar Akbar S Khan Vito G DelVecchio 《Proteome science》2007,5(1):11-10
Background
The secretion time course of Bacillus anthracis strain RA3R (pXO1+/pXO2-) during early, mid, and late log phase were investigated under conditions that simulate those encountered in the host. All of the identified proteins were analyzed by different software algorithms to characterize their predicted mode of secretion and cellular localization. In addition, immunogenic proteins were identified using sera from humans with cutaneous anthrax. 相似文献43.
Penaeid and carid communities were assessed in St Lucia over a wide range of saline conditions, water level conditions and mouth states, including a six-month marine connection and various connections to the Mfolozi Estuary. Samples were collected biannually in spring and autumn from November 2004 to May 2012 using seine nets. Seven penaeid and seven carid species were recorded, of which Palaemon pacificus, P. peringueyi, Penaeus indicus and Metapenaeus monoceros were the most abundant. The decline from 2004 to 2007 in both species recorded and densities of freshwater, estuarine and marine species during the initial closed period was linked to increased salinity, lack of recruitment and reduced estuarine surface area. Increased wave action and high seas following Cyclone Gamede opened the mouth in March 2007 after a 57-month closed period, resulting in recruitment of marine species, predominantly P. indicus, followed by a decline in densities after reclosure in August 2007. Increases in marine and freshwater species were evident after Mfolozi flood connections during 2008, 2009 and 2010. Highest densities were recorded after breaching in 2007 and after flood connections, highlighting the importance of a marine link to maintain the recruitment of penaeid species. 相似文献
44.
S Q Cheng R E Musso R Liu D M Niemeyer J J Shaw F K McCleskey V G DelVecchio 《Plasmid》1999,42(1):42-44
We have cloned and identified an insertion sequence, IS1485, that was present in several members of the genus Enterococcus. IS1485 exists in varying copy numbers with at least 12 copies in E. durans (ATCC 11576), 3 copies in E. faecium (ATCC 19434), and one copy each in E. faecalis (ATCC 19433) and E. avium (ATCC 14024). It was also detected in clinical strains of E. gallinarum, E. casseliflavus, and E. saccharolyticus. IS1485 is 1366 bp in length, it has imperfect terminal inverted repeats with 25 of the terminal 39 residues matched, and it contains three open reading frames exceeding 50 codons, designated orfA, orfB, and orfC. The largest, orfB, was located 36 bp downstream and in the -1 reading frame relative to orfA; orfC is oriented in the opposite direction and overlaps orfA. The genetic organization of IS1485 resembles that of members of the IS3 family of transposable elements. Sequence homology exists with several members of the IS3 family especially with IS199 from Streptococcus mutans. 相似文献
45.
Culture, Medicine, and Psychiatry - 相似文献
46.
Sheila C Rahal Reinaldo S Volpi Carlos R Teixeira Vania MV Machado Guilherme DP Soares Carlos Ramires Neto Kathleen Linn 《BMC veterinary research》2012,8(1):1-5
Background
Although Morbillivirus and Toxoplasma gondii have emerged as important pathogens for several cetaceans populations over the last 20 years, they have never been identified together in a Mysticete. In particular, morbilliviral infection has been never described in the Mediterranean fin whale population.Case presentation
On January 2011 an adult male of fin whale (Balaenoptera physalus) stranded along the Tyrrhenian coastline of Italy. During necropsy, tissue samples from heart, skeletal muscle, mesenteric lymph nodes, liver, spleen, lung, and kidney were collected and subsequently analyzed for Morbillivirus and Toxoplasma gondii by microscopic and molecular methods. Following the detailed necropsy carried out on this whale, molecular analysis revealed, for the first time, the simultaneous presence of a Dolphin Morbillivirus (DMV) and T. gondii infection coexisting with each other, along with high organochlorine pollutant concentrations, with special reference to DDT.Conclusion
This report, besides confirming the possibility for Mysticetes to be infected with DMV, highlights the risk of toxoplasmosis in sea water for mammals, already immunodepressed by concurrent factors as infections and environmental contaminants. 相似文献47.
48.
We investigated the effects of audiovisual compound training on song learning in zebra finches, Taeniopygia guttata. In the first experiment, presentation of a stuffed adult zebra finch male was found to be reinforcing to zebra finch males in an operant task. In a separate experiment, zebra finch males were reared without their father from day 7 after hatching onwards. Between 35 and 76 days, they were placed in isolation and exposed to taped songs of a zebra finch male, according to a random schedule (20 presentations/h). For half of the birds, presentation of the song coincided with presentation of a stuffed zebra finch male. For the remaining birds, each presentation of the song was followed by presentation of a stuffed male. The birds were subsequently isolated until day 142, when their own songs were recorded and analysed. Birds in both groups shared significantly more song elements with their tutor songs than with an unfamiliar song. There was no significant difference in song learning between the groups. These results confirm that zebra finches can learn part of their songs from taped tutor songs. Furthermore, simultaneous presentation of the tutor song and a relevant, salient visual stimulus is not superior to sequential presentation. Copyright 1999 The Association for the Study of Animal Behaviour. 相似文献
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