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International Journal of Primatology - Over the past decades, primate populations have been declining. Four years ago, >60% of species were listed as threatened. As the rate of loss...  相似文献   
994.

Background  

Alzheimer's disease (AD) is the most common cause of dementia characterized by progressive cognitive impairment in the elderly people. The most dramatic abnormalities are those of the cholinergic system. Acetylcholinesterase (AChE) plays a key role in the regulation of the cholinergic system, and hence, inhibition of AChE has emerged as one of the most promising strategies for the treatment of AD.  相似文献   
995.
Germline-specific Cre lines are useful for analyses of primordial germ cell, spermatogonial and oogonial development, but also for whole-body deletions when transmitted through subsequent generations. Several germ cell specific Cre mouse strains exist, with various degrees of specificity, efficiency, and temporal activation. Here, we describe the CRISPR/Cas9 targeted insertion of an improved Cre (iCre) sequence in-frame at the 3′ end of the Ddx4 locus to generate the Ddx4-P2A-iCre allele. Our functional assessment of this new allele, designated Ddx4iCreJoBo, reveals that Cre activity begins in PGCs from at least E10.5, and that it achieves higher efficiency for early gonadal (E10.5–12.5) germline deletion when compared to the inducible Oct4CreERT2 line. We found the Ddx4iCreJoBo allele to be hypomorphic for Ddx4 expression and homozygous males, but not females, were infertile. Using two reporter lines (R26RLacZ and R26RtdTomato) and a floxed gene of interest (Criptoflox) we found ectopic activity in multiple organs; global recombination (a common feature of germline Cre alleles) varies from 10 to 100%, depending on the particular floxed allele. There is a strong maternal effect, and therefore it is preferable for Ddx4iCreJoBo to be inherited from the male parent if ubiquitous deletion is not desired. With these limitations considered, we describe the Ddx4iCreJoBo line as useful for germline studies in which early gonadal deletion is required.  相似文献   
996.
Summary Ascorbic acid reduced the agglutination activities of the various strains of Newcastle disease and fowl-plague viruses used but was in-effective with respects to their infectivity powers.  相似文献   
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Summary Crystal violet in concentrations above 100 p.p.m. induced appreciable inhibition of the hemagglutination and infectivity powers of the various strains of Newcastle disease and fowl-plague viruses being tested.  相似文献   
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Studies of convergence in wild populations have been instrumental in understanding adaptation by providing strong evidence for natural selection. At the genetic level, we are beginning to appreciate that the re-use of the same genes in adaptation occurs through different mechanisms and can be constrained by underlying trait architectures and demographic characteristics of natural populations. Here, we explore these processes in naturally adapted high- (HP) and low-predation (LP) populations of the Trinidadian guppy, Poecilia reticulata. As a model for phenotypic change this system provided some of the earliest evidence of rapid and repeatable evolution in vertebrates; the genetic basis of which has yet to be studied at the whole-genome level. We collected whole-genome sequencing data from ten populations (176 individuals) representing five independent HP-LP river pairs across the three main drainages in Northern Trinidad. We evaluate population structure, uncovering several LP bottlenecks and variable between-river introgression that can lead to constraints on the sharing of adaptive variation between populations. Consequently, we found limited selection on common genes or loci across all drainages. Using a pathway type analysis, however, we find evidence of repeated selection on different genes involved in cadherin signaling. Finally, we found a large repeatedly selected haplotype on chromosome 20 in three rivers from the same drainage. Taken together, despite limited sharing of adaptive variation among rivers, we found evidence of convergent evolution associated with HP-LP environments in pathways across divergent drainages and at a previously unreported candidate haplotype within a drainage.  相似文献   
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