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111.
Proteolytic processing of mullerian inhibiting substance produces a transforming growth factor-beta-like fragment 总被引:4,自引:0,他引:4
R B Pepinsky L K Sinclair E P Chow R J Mattaliano T F Manganaro P K Donahoe R L Cate 《The Journal of biological chemistry》1988,263(35):18961-18964
Mullerian inhibiting substance (MIS) is a differentiation factor that causes the Mullerian duct to regress during the development of the male reproductive tract. The active form is a disulfide-linked dimer consisting of two identical 70-kDa subunits. Recently, the amino acid sequence for MIS was deduced from its gene sequence and revealed that the carboxyl-terminal region shares homology with transforming growth factor (TGF)-beta. Since TGF-beta is produced as a large latent precursor that requires proteolytic activation for activity, we sought to determine if MIS might undergo a similar processing event. Here we demonstrate that typically 5 to 20% of the protein in MIS preparations is cleaved at a site 109 amino acids from the carboxyl terminus. Concurrent cleavages from both chains of the MIS dimer produces a 25-kDa TGF-beta-like fragment and a high molecular mass complex derived from the amino terminus of the protein. Although the two fragments are noncovalently linked, they remain tightly associated after cleavage, and thus are structurally organized like TGF-beta within its precursor. The same cleavage products also can be generated by limited proteolysis with plasmin, which provides a simple method for converting the entire preparation into the cleaved form. The plasmin-digested MIS is fully active in the organ culture assay. 相似文献
112.
V N Meyers-Wallen P K Donahoe T Manganaro D F Patterson 《Biology of reproduction》1987,37(4):1015-1022
In normal males, Müllerian Inhibiting Substance (MIS), produced by testes during an embryonic critical period, is thought to induce regression of the Müllerian duct system, including the oviducts and uterus. In XX sex-reversed dogs, an apparent contradiction has been reported: The uterus persists in the presence of testes or ovotestes. The objective of this study is to determine whether testes of XX male and ovotestes of true hermaphrodite dogs produce MIS, and to examine the anatomy of Müllerian duct derivatives of affected dogs for evidence of regression. Gonadal samples were tested for MIS activity in a bioassay. The mean MIS activity score of XX males was similar to that of normal XY males and significantly greater than that of normal XX females. The mean MIS activity score of XX true hermaphrodites was intermediate between normal XX females and XY males. Within the true hermaphrodite group, ovotestes in which the proportion of testicular tissue was greater than or equal to 1/2 had higher MIS scores than those in which the proportion of testicular tissue was less than 1/2. XX males had a well-developed epididymis adjacent to each testis, but no oviducts. In true hermaphrodites, the oviduct regressed and an epididymis was present when greater than or equal to 1/2 of the adjacent ovotestis was testicular, and MIS activity in that gonad was high. A few ovotestes with intermediate levels of MIS activity had both an oviduct and an epididymis. Regression of the oviductal portion of the Müllerian duct system was positively correlated to the amount of testicular tissue and the MIS activity of the gonad, as would be predicted by Jost's original hypothesis.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
113.
Evidence from nuclear sequences that invariable sites should be considered when sequence divergence is calculated 总被引:3,自引:1,他引:2
It has long been known, from the distribution of multiple amino acid
replacements, that not all amino acids of a sequence are replaceable. More
recently, the phenomenon was observed at the nucleotide level in
mitochondrial DNA even after allowing for different rates of transition and
transversion substitutions. We have extended the search to globin gene
sequences from various organisms, with the following results: (1) Nearly
every data set showed evidence of invariable nucleotide positions. (2) In
all data sets, substitution rates of transversions and transitions were
never in the ratio of 2/1, and rarely was the ratio even constant. (3) Only
rarely (e.g., the third codon position of beta hemoglobins) was it possible
to fit the data set solely by making allowance for the number of invariable
positions and for the relative rates of transversion and transition
substitutions. (4) For one data set (the second codon position of beta
hemoglobins) we were able to simulate the observed data by making the
allowance in (3) and having the set of covariotides (concomitantly variable
nucleotides) be small in number and be turned over in a stochastic manner
with a probability that was appreciable. (5) The fit in the latter case
suggests, if the assumptions are correct and at all common, that current
procedures for estimating the total number of nucleotide substitutions in
two genes since their divergence from their common ancestor could be low by
as much as an order of magnitude. (6) The fact that only a small fraction
of the nucleotide positions differ is no guarantee that one is not
seriously underestimating the total amount of divergence (substitutions).
(7) Most data sets are so heterogeneous in their number of transition and
transversion differences that none of the current models of nucleotide
substitution seem to fit them even after (a) segregation of coding from
noncoding sequences and (b) splitting of the codon into three subsets by
codon position. (8) These frequently occurring problems cannot be seen
unless several reasonably divergent orthologous genes are examined
together.
相似文献
114.
Akira Hayashi Patricia K. Donahoe Gerald P. Budzik Robert L. Trelstad 《Developmental biology》1982,92(1):16-26
Gonadal ridges containing Mullerian and Wolffian ducts were removed from rat embryos from Days 14 through 16 of gestation and their production of glycoprotein, hyaluronate, and sulfated glycosaminoglycans examined. Autoradiographic, histochemical, and biochemical studies indicate that the periductal zone contains hyaluronate and sulfated glycosaminoglycans, that these matrix constituents are degraded during development, and that the proportions of glycosaminoglycans accumulated by isolated female gonadal ridges in vitro can be altered by the addition of Mullerian inhibiting substance to the culture medium. When the Mullerian duct regressed there was an unexpected persistence of labeled glucosamine derivatives in cells in the mesenchymal cell space suggesting that some such cells are dissociated ductal epithelial cells which have transformed into mesenchyme. 相似文献
115.
116.
V N Meyers-Wallen P K Donahoe S Ueno T F Manganaro D F Patterson 《Biology of reproduction》1989,41(5):881-888
Breeding studies in a strain of miniature schnauzer dogs with Persistent Müllerian Duct Syndrome (PMDS) indicate this syndrome is inherited as an autosomal recessive trait, as it is in man. Testes of neonatal dogs affected with PMDS and normal male littermates were examined for Müllerian Inhibiting Substance (MIS) production by immunohistochemistry and bioassay. MIS immunoactivity was detected in Sertoli cells of normal and affected pups using an avidin-biotin complex-enhanced method. Rat embryonic Müllerian ducts regressed when cocultured with testis fragments of both normal and affected pups in a graded organ culture bioassay, demonstrating that the MIS produced was bioactive. These findings indicate that Müllerian duct persistence in affected dogs is not due to a mutation in the structural gene for MIS, but rather, by inference, to a failure of response to MIS at the receptor level. 相似文献
117.
Bayesian adaptive sequence alignment algorithms 总被引:3,自引:1,他引:2
The selection of a scoring matrix and gap penalty parameters continues to
be an important problem in sequence alignment. We describe here an
algorithm, the 'Bayes block aligner, which bypasses this requirement.
Instead of requiring a fixed set of parameter settings, this algorithm
returns the Bayesian posterior probability for the number of gaps and for
the scoring matrices in any series of interest. Furthermore, instead of
returning the single best alignment for the chosen parameter settings, this
algorithm returns the posterior distribution of all alignments considering
the full range of gapping and scoring matrices selected, weighing each in
proportion to its probability based on the data. We compared the Bayes
aligner with the popular Smith-Waterman algorithm with parameter settings
from the literature which had been optimized for the identification of
structural neighbors, and found that the Bayes aligner correctly identified
more structural neighbors. In a detailed examination of the alignment of a
pair of kinase and a pair of GTPase sequences, we illustrate the
algorithm's potential to identify subsequences that are conserved to
different degrees. In addition, this example shows that the Bayes aligner
returns an alignment-free assessment of the distance between a pair of
sequences.
相似文献
118.
119.
Reta-Sánchez DG JS Serrato-Corona HM Quiroga-Garza A Gaytán-Mascorro JA Cueto-Wong 《Phyton》2015,84(2):262-271
Kenaf (Hibiscus cannabinus L.) forage potential can be enhanced through its regrowth capacity and higher production in narrow rows. A field experiment was conducted in Matamoros, Coahuila, Mexico, during 2 growing seasons (2004 and 2005) to study the effects of plant height and row spacing on kenaf forage potential with multiple harvests. This study evaluated the effects of (1) 2 plant heights at cutting (1.0-1.2 m and 1.8-2.0 m) and (2) 4 inter row spacings (0.19, 0.38, 0.57 and 0.76 m) using a 2 x 4 factorial arrangement of treatments in a completely randomized block design with 4 replications. Dry matter (DM) and crude protein (CP) yields, DM partitioning, neutral detergent fiber (NDF) and CP concentrations were determined. Heights at cutting × row spacing interactions were not significant for the monitored variables (p>0.05). Kenaf response to treatments was only relevant for main effects (p≤0.05). Row spacing and plant height affected DM and CP yields (p≤0.05), whereas only plant height affected chemical composition and DM partitioning (p≤0.05). Dry matter (17.0%-26.0%), and CP (12.4%-15.6%) yields were higher (p≤0.05) when plant heights had reached 1.8 to 2.0 m. Row spacing reduction from 0.76 m to 0.38 and 0.19 m increased DM yield (20.4-33.4%) and CP yield (24.2-38.5%) (p≤0.05). Kenaf forage potential increases when planted in narrow rows and harvested 2 or 3 times during the growing season. 相似文献
120.
Gutiérrez-Guzmán UN E Castellanos-Pérez JJ Q uiñones-Vera JS Serrato-Corona JJ Martínez-Ríos I Orona-Castillo I Chairez-Hernández 《Phyton》2015,84(2):312-318
A regression model was used to determine the relationship between aerial herbaceous biomass and vegetation coverage estimated by digital images. Four samplings (n=36 each date) of vegetation cover and herbaceous biomass were performed during the growing season in 2011 in a grassland dominated by Bouteloua gracilis in La Cieneguilla, Municipality of Villa Hidalgo, Durango. Average production of dry biomass was 37.36 ± 9.66 g/m2, and mean vegetation cover 30.02%. Dry biomass data were tested for normality using the test of Kolmogorov Smirnov, finding a lack of fit. The data were subjected to a logarithmic transformation and the model Ln(y) = 1.637926 + 0.08501X - 0.000586X2 with an adjusted R2 = 0.89 was found. In order to validate this model, another five samplings were carried out in 2013 at the same site during summer and autumn, using the same sampling size for each date as in 2011. Data collected in 2013 were analyzed with the model Ln (y) = β0 + β1X + β2X2. A comparison of regression coefficients was carried out between the 2011 and 2013 models with t (180+144-9-11-2=302, p<0.05) = 1.967. The results indicated that it is possible to use the 2011 regression model to estimate herbaceous aerial biomass from vegetation cover measurements with aerial photographs in La Cieneguilla site during summer and fall. 相似文献