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1.
The differentiation of spermatids in the marmoset (Callithrix jacchus, n = 9) testis is described here at the light-microscopic level employing serial semithin sections. The definition of 8 different phases of spermiogenesis, i.e. the formation of spermatids, is based upon the changes in the development of nucleus, acrosome and flagellum. 相似文献
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Vasant Chellappa Kendra N. Taylor Kathryn Pedrick Carlos Donado Ilka Arun Netravali Khaleda Haider Annaiah Cariappa Natasha F. Dalomba Shiv Pillai 《PloS one》2013,8(1)
Catalytically defective rare variants of Sialic acid Acetyl Esterase (SIAE) have previously been linked to autoimmunity. Studies presented here confirm that the M89V SIAE protein and all other products of common variant alleles of SIAE are catalytically normal. Although overexpressing transfected non-lymphoid cells secrete small amounts of SIAE that can associate with the cell surface, normal human lymphocytes do not exhibit cell surface SIAE, supporting genetic evidence in mice that indicates that this protein functions in a lymphocyte intrinsic manner. Analyses of the plasma proteome also indicate that SIAE is not secreted in vivo. A re-analysis exclusively of catalytically defective rare variant alleles of SIAE in subjects in which this gene was completely sequenced confirmed an association of SIAE with autoimmunity. A subset of catalytically defective rare variant SIAE alleles has previously been typed in a large genotyping study comparing a diverse group of disease subjects and controls; our re-analysis of this data shows that catalytically defective alleles are enriched in disease subjects. These data suggest that SIAE may be associated with autoimmunity and that further study of catalytically defective rare variant SIAE alleles in terms of autoimmune disease susceptibility is strongly warranted. 相似文献
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Pervez Haider Zaidi Zerka Rashid Madhumal Thayil Vinayan Gustavo Dias Almeida Ramesh Kumar Phagna Raman Babu 《PloS one》2015,10(4)
Waterlogging is an important abiotic stress constraint that causes significant yield losses in maize grown throughout south and south-east Asia due to erratic rainfall patterns. The most economic option to offset the damage caused by waterlogging is to genetically incorporate tolerance in cultivars that are grown widely in the target agro-ecologies. We assessed the genetic variation in a population of recombinant inbred lines (RILs) derived from crossing a waterlogging tolerant line (CAWL-46-3-1) to an elite but sensitive line (CML311-2-1-3) and observed significant range of variation for grain yield (GY) under waterlogging stress along with a number of other secondary traits such as brace roots (BR), chlorophyll content (SPAD), % stem and root lodging (S&RL) among the RILs. Significant positive correlation of GY with BR and SPAD and negative correlation with S&RL indicated the potential use of these secondary traits in selection indices under waterlogged conditions. RILs were genotyped with 331 polymorphic single nucleotide polymorphism (SNP) markers using KASP (Kompetitive Allele Specific PCR) Platform. QTL mapping revealed five QTL on chromosomes 1, 3, 5, 7 and 10, which together explained approximately 30% of phenotypic variance for GY based on evaluation of RIL families under waterlogged conditions, with effects ranging from 520 to 640 kg/ha for individual genomic regions. 13 QTL were identified for various secondary traits associated with waterlogging tolerance, each individually explaining from 3 to 14% of phenotypic variance. Of the 22 candidate genes with known functional domains identified within the physical intervals delimited by the flanking markers of the QTL influencing GY and other secondary traits, six have previously been demonstrated to be associated with anaerobic responses in either maize or other model species. A pair of flanking SNP markers has been identified for each of the QTL and high throughput marker assays were developed to facilitate rapid introgression of waterlogging tolerance in tropical maize breeding programs. 相似文献
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Biomechanics and Modeling in Mechanobiology - Cartilage tissue engineering is commonly initiated by seeding cells in porous materials such as hydrogels or scaffolds. Under optimal conditions, the... 相似文献
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Sonja Maria Hansen Hilde Haider Alexandra Eichler Claudia Godau Peter A. Frensch Robert Gaschler 《PloS one》2015,10(11)
How can we enhance the understanding of abstract mathematical principles in
elementary school? Different studies found out that nonsymbolic estimation could
foster subsequent exact number processing and simple arithmetic. Taking the
commutativity principle as a test case, we investigated if the approximate
calculation of symbolic commutative quantities can also alter the access to
procedural and conceptual knowledge of a more abstract arithmetic principle.
Experiment 1 tested first graders who had not been instructed about
commutativity in school yet. Approximate calculation with symbolic quantities
positively influenced the use of commutativity-based shortcuts in formal
arithmetic. We replicated this finding with older first graders (Experiment 2) and third graders (Experiment 3). Despite the positive
effect of approximation on the spontaneous application of commutativity-based
shortcuts in arithmetic problems, we found no comparable impact on the
application of conceptual knowledge of the commutativity principle. Overall, our
results show that the usage of a specific arithmetic principle can benefit from
approximation. However, the findings also suggest that the correct use of
certain procedures does not always imply conceptual understanding. Rather, the
conceptual understanding of commutativity seems to lag behind procedural
proficiency during elementary school. 相似文献
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