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121.
Pask AJ Whitworth DJ Mao CA Wei KJ Sankovic N Graves JA Shaw G Renfree MB Behringer RR 《Biology of reproduction》2004,70(1):160-167
During male sexual development in reptiles, birds, and mammals, anti-Müllerian hormone (AMH) induces the regression of the Müllerian ducts that normally form the primordia of the female reproductive tract. Whereas Müllerian duct regression occurs during fetal development in eutherian mammals, in marsupial mammals this process occurs after birth. To investigate AMH in a marsupial, we isolated an orthologue from the tammar wallaby (Macropus eugenii) and characterized its expression in the testes and ovaries during development. The wallaby AMH gene is highly conserved with the eutherian orthologues that have been studied, particularly within the encoded C-terminal mature domain. The N-terminus of marsupial AMH is divergent and larger than that of eutherian species. It is located on chromosome 3/4, consistent with its autosomal localization in other species. The wallaby 5' regulatory region, like eutherian AMH genes, contains binding sites for SF1, SOX9, and GATA factors but also contains a putative SRY-binding site. AMH expression in the developing testis begins at the time of seminiferous cord formation at 2 days post partum, and Müllerian duct regression begins shortly afterward. In the developing testis, AMH is localized in the cytoplasm of the Sertoli cells but is lost by adulthood. In the developing ovary, there is no detectable AMH expression, but in adults it is produced by the granulosa cells of primary and secondary follicles. It is not detectable in atretic follicles. Collectively, these studies suggest that AMH expression has been conserved during mammalian evolution and is intimately linked to upstream sex determination mechanisms. 相似文献
122.
Stanton T Boxall S Bennett A Kaleebu P Watera C Whitworth J French N Dawes R Hill AV Bodmer W Beverley PC Tchilian EZ 《Immunogenetics》2004,56(2):107-110
The CD45 (leucocyte common) antigen is a haemopoietic cell specific tyrosine phosphatase essential for antigen receptor signalling in lymphocytes, and expression of different CD45 isoforms is associated with distinct functions. Here we describe a novel polymorphism in exon 4 (A54G) of the gene encoding CD45 (PTPRC) that results in an amino acid substitution of Thr-19 to Ala in exon 4. The 54G allele was identified in African Ugandan populations and was found with a suggestive but not statistically significant increase in frequency amongst HIV-seropositive Ugandans. This suggests that the 54G variant and CD45 splicing abnormalities might be associated with HIV infection. 相似文献
123.
Buckley GM Davies N Dyke HJ Gilbert PJ Hannah DR Haughan AF Hunt CA Pitt WR Profit RH Ray NC Richard MD Sharpe A Taylor AJ Whitworth JM Williams SC 《Bioorganic & medicinal chemistry letters》2005,15(3):751-754
The development of a series of novel quinazolinethiones and quinazolinediones as inhibitors of inosine monophosphate dehydrogenase (IMPDH) is described. The synthesis, in vitro inhibitory values for IMPDH II and in vitro inhibitory value for PBMC proliferation are discussed. 相似文献
124.
Rapid evolution of immunoglobulin superfamily C2 domains expressed in immune system cells 总被引:6,自引:3,他引:3
To test the hypothesis that proteins expressed in cells of the vertebrate
immune system evolve unusually rapidly, 107 orthologous immunoglobulin C2
domains were compared between human and murine rodent. The analysis showed
that the rate of nonsynonymous (amino-acid- altering) nucleotide
substitution in these domains was correlated with factors associated with
protein structure and with breadth of tissue expression, as well as with
the rate of synonymous substitution. However, when such factors were
controlled for statistically, there remained a strong positive association
between expression in the immune system and nonsynonymous rate, with the
highest rates being seen in genes expressed in the immune system only.
Certain immune system genes are known to be subject to positive selection
favoring diversity at the amino acid level; most of these genes encode
receptors that interact directly with foreign antigens. The observed
acceleration of the rate of nonsynonymous evolution in C2 domains of immune
system proteins may be explained by either (1) reduced constraint at the
amino acid level on molecules interacting with immune system receptors that
are themselves evolving rapidly due to positive diversifying selection or
(2) positive selection favoring amino acid changes correlated with changes
in the immune system receptors.
相似文献
125.
Shaonpius Mondal Erik J. Wenninger Pamela J.S. Hutchinson Jonathan L. Whitworth Deepak Shrestha Sanford D. Eigenbrode Nilsa A. Bosque‐Pérez 《Entomologia Experimentalis et Applicata》2016,158(3):258-268
Potato virus Y (PVY) strains are transmitted by different aphid species in a non‐persistent, non‐circulative manner. Green peach aphid (GPA), Myzus persicae Sulzer, is the most efficient vector in laboratory studies, but potato aphid (PA), Macrosiphum euphorbiae Thomas (both Hemiptera: Aphididae, Macrosiphini), and bird cherry‐oat aphid (BCOA), Rhopalosiphum padi L. (Hemiptera: Aphididae, Aphidini), also contribute to PVY transmission. Studies were conducted with GPA, PA, and BCOA to assess PVY transmission efficiency for various isolates of the same strain. Treatments included three PVY strains (PVYO, PVYN:O, PVYNTN) and two isolates of each strain (Oz and NY090031 for PVYO; Alt and NY090004 for PVYN:O; N4 and NY090029 for PVYNTN), using each of three aphid species as well as a sham inoculation. Virus‐free tissue‐cultured plantlets of potato cv. Russet Burbank were used as virus source and recipient plants. Five weeks post inoculation, recipient plants were tested with quantitative DAS‐ELISA to assess infection percentage and virus titer. ELISA‐positive recipient plants were assayed with RT‐PCR to confirm presence of the expected strains. Transmission efficiency (percentage infection of plants) was highest for GPA, intermediate for BCOA, and lowest for PA. For all aphid species, transmission efficiency did not differ significantly between isolates within each strain. No correlations were found among source plant titer, infection percentage, and recipient plant titer. For both GPA and BCOA, isolates of PVYNTN were transmitted with greatest efficiency followed by isolates of PVYO and PVYN:O, which might help explain the increasing prevalence of necrotic strains in potato‐growing regions. Bird cherry‐oat aphid transmitted PVY with higher efficiency than previously reported, suggesting that this species is more important to PVY epidemiology than has been considered. 相似文献
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129.
Derek C. Prosser Karen Whitworth Beverly Wendland 《Traffic (Copenhagen, Denmark)》2010,11(9):1141-1150
The pH‐sensitive green fluorescent protein (GFP) variant pHluorin is typically fused to the extracellular domain of transmembrane proteins to monitor endocytosis. Here, we have turned pHluorin inside‐out, and show that cytoplasmic fusions of pHluorin are effective quantitative reporters for endocytosis and multivesicular body (MVB) sorting. In yeast in particular, fusion of GFP and its variants on the extracellular side of transmembrane proteins can result in perturbed trafficking. In contrast, cytoplasmic fusions are well tolerated, allowing for the quantitative assessment of trafficking of virtually any transmembrane protein. Quenching of degradation‐resistant pHluorin in the acidic vacuole permits quantification of extravacuolar cargo proteins at steady‐state levels and is compatible with kinetic analysis of endocytosis in live cells. 相似文献
130.
OMAR HAMARSHEH WOLFGANG PRESBER ZIAD ABDEEN SAMER SAWALHA AHMAD AL‐LAHEM GABRIELE SCHOENIAN 《Molecular ecology resources》2006,6(3):826-828
Phlebotomus papatasi is a proven vector of Leishmania major which is one of the causative agents of cutaneous leishmaniasis in the Old World. Although it has a wide geographical range, its population structure is not yet well understood. In an effort to better understand the population dynamics of this vector, we developed a panel of di‐ and trinucleotide microsatellite markers, using a magnetic bead hybridization enrichment protocol. These microsatellite loci showed three to seven alleles with an expected heterozygosity range between 0.702 and 0.876. The level of polymorphisms found in this study suggests that these microsatellite loci can be used for population analysis of P. papatasi. 相似文献