Life Sciences Commons^™

Mullerian Inhibiting Substance Inhibits Testosterone Synthesis In Adult Rats, V. Sriraman, E. Niu, J. Matias, Patricia Donahoe, David Maclaughlin, Matthew Hardy, Mary Lee

Mary M. Lee

Mullerian inhibiting substance (MIS) is a gonadal hormone that causes regression of the Mullerian ducts during male sexual differentiation. Postnatally, MIS inhibits the proliferation and differentiation of immature Leydig cells, and transgenic mice that overexpress MIS have decreased serum testosterone concentrations. To elucidate the effects of MIS on androgen regulation in the postnatal testis, we examined testosterone synthesis in adult Sprague-Dawley rats following intratesticular and intraperitoneal injections of MIS. Intratesticular MIS injection achieved high local concentrations of MIS (574.0 +/- 60.0 ng/mL) at 4 hours, with a corresponding decline in serum testosterone concentrations to 0.7 +/- 0.1 ng/mL, compared to …

Developmental Changes In Mullerian Inhibiting Substance In The Cynomolgus Monkey, Macaca Fascicularis, Mary Lee, M. Gustafson, Etsuji Ukiyama, Patricia Donahoe, David Maclaughlin, Michael Wexler, Hugh Keeping

Mary M. Lee

Mullerian inhibiting substance (MIS) is a glycoprotein hormone produced in Sertoli cells of the fetal and postnatal testis, and granulosa cells of the pubertal ovary. We examined MIS expression in a nonhuman primate, the cynomolgus macaque monkey (Macaca fascicularis), to define an animal model for studying MIS gene regulation. Changes in testicular MIS mRNA with age were assessed by in situ hybridization of prepubertal to adult testes, Northern analysis of pubertal and adult specimens, and determination of serum MIS concentrations from infancy to adulthood. We found that MIS expression was highest in the youngest animals and decreased progressively with increasing …

Mullerian-Inhibiting Substance Type Ii Receptor Expression And Function In Purified Rat Leydig Cells, Mary Lee, C. Seah, P. Masiakos, Chantal Sottas, F. Preffer, Patricia Donahoe, David Maclaughlin, Matthew Hardy

Mary M. Lee

Mullerian-inhibiting substance (MIS), a gonadal hormone in the transforming growth factor-beta superfamily, induces Mullerian duct involution during male sexual differentiation. Mice with null mutations of the MIS ligand or receptor develop Leydig cell hyperplasia and neoplasia in addition to retained Mullerian ducts, whereas MIS-overexpressing transgenic mice have decreased testosterone concentrations and Leydig cell numbers. We hypothesized that MIS directly modulates Leydig cell proliferation and differentiated function in the maturing testis. Therefore, highly purified rat Leydig and Sertoli cells were isolated to examine cell-specific expression, binding, and function of the MIS type II receptor. These studies revealed that this receptor is …

Isolation Of The Rat Gene For Mullerian Inhibiting Substance, Christopher Haqq, Mary Lee, Richard Tizard, Mark Wysk, Janice Demarinis, Patricia Donahoe, Richard Cate

Mary M. Lee

Mullerian inhibiting substance (MIS), a testicular glycoprotein also known as anti-Mullerian hormone, plays a key role in male sexual development by causing regression of the Mullerian duct, the anlagen of the uterus, the Fallopian tubes, and part of the vagina. MIS is also expressed in the postnatal ovary, but its precise function is still not known. We report here the complete nucleotide sequence of the rat MIS gene. Rat MIS is encoded in five exons and is synthesized as a precursor of 553 amino acids, containing a 24-amino-acid leader. Based on homology with human MIS, we predict that the rat …

Diagnostic Utility Of Mullerian Inhibiting Substance Determination In Patients With Primary And Recurrent Granulosa Cell Tumors, Andrew Lane, Mary Lee, Arlan Fuller, David Kehas, Patricia Donahoe, David Maclaughlin

Mary M. Lee

OBJECTIVES: In this study we evaluated changes in serum Mullerian inhibiting substance (MIS) concentration in a large number of patients with granulosa cell tumors (GCT) to determine whether MIS is elevated at the time of presentation and whether MIS is an index of successful surgical resection and management of recurrences. METHODS: We retrospectively reviewed MIS levels from 17 subjects prior to tumor resection and studied serial MIS samples from 56 subjects following initial tumor resection. Clinical follow-up information was available for 36 of those with postoperative MIS values. Serum MIS was measured by an ELISA. MIS values were compared to …

Serum Adrenal Steroid Concentrations In Premature Infants, Mary Lee, Lakshmy Rajagopalan, Gregory Berg, Thomas Moshang

Mary M. Lee

To evaluate serum adrenal steroid concentrations in preterm infants, 17-hydroxyprogesterone (17-OHP), 17-hydroxypregnenolone, 11-deoxycortisol, cortisol, dehydroepiandrosterone (DHEA), DHEA sulfate, androstenedione, 18-hydroxycorticosterone, and aldosterone values were determined in 9 sick and 13 healthy premature infants. Serum steroid concentrations were compared to previously reported data from healthy full-term infants. 17-OHP, 11-deoxycortisol, and aldosterone values were higher in sick preterm infants than in healthy preterm infants. Compared to healthy full-term infants, the premature infants-had significantly higher 17-hydroxypregnenolone, 17-OHP, and DHEA sulfate concentrations. Cortisol values were not different between the sick and healthy preterm infants and were similar to full-term values. Aldosterone values were also …

Clinical Management Of Intersex Abnormalities, Patricia Donahoe, David Powell, Mary Lee

Mary M. Lee

No abstract provided.

Effect Of E. Coli Endotoxin On Mammalian Cell Growth And Recombinant Protein Production, J. Epstein, Mary Lee, C. Kelly, Patricia Donahoe

Mary M. Lee

No abstract provided.

Physical Growth And Sexual Maturation Of Boys In Chapaevsk, Russia, Mary Lee, Oleg Sergeyev, Paige Williams, Susan Korrick, Vladimir Zeilert, Boris Revich, Russ Hauser

Mary M. Lee

We characterized physical growth and sexual maturation in 2,579 boys, ages 10 through 16.99 years, residing in Chapaevsk, Russia in order to establish region-specific reference data. Age-specific norms were established for height, weight, and BMI, and compared to US reference data by z-score analysis, while mean heights and weights by age were compared to published national Russian data. Compared to US boys, height was slightly lower (overall z-score -0.18) at all ages except the oldest (16-16.99 yr), while weight and BMI were moderately lower (overall z-score -0.52 and -0.61, respectively). Chapaevsk boys were significantly taller (1.15 cm) and thinner (-1.28 …

Mullerian Inhibiting Substance Messenger Ribonucleic Acid Expression In Granulosa And Sertoli Cells Coincides With Their Mitotic Activity, Seiichi Hirobe, Wei He, Mary Lee, Patricia Donahoe

Mary M. Lee

In males, Mullerian inhibiting substance (MIS) mRNA was first detected on the medial aspect of the urogenital ridge early on the morning of day 13 of gestation before testicular differentiation was evident, and localized to the more obvious Sertoli cells later on embryonic day 13. MIS transcripts remained at maximal levels between 14.5 and 17.5 days gestation, while the Mullerian duct involutes, and remained high until birth. MIS gene expression decreased progressively after birth and, as germ cell meiosis increased, became barely detectable in the Sertoli cells of the seminiferous tubules. In female rats, MIS mRNA was first detected in …

Guidelines For The Use Of Growth Hormone In Children With Short Stature., Mary Lee

Mary M. Lee

On the basis of the information currently available, the only conditions in which GH therapy appears to be safe and effective in increasing adult height are GH deficiency and, likely, Turner syndrome. Therapy with GH also increases the growth velocity of children with CRI and may increase adult height, but no long-term data are available. Encouraging short-term results have been reported in patients with a few other conditions, such as patients with glucocorticoid-induced growth failure, renal transplantation, and Prader-Willi syndrome, but the data are limited and no long-term studies have been reported; in many other conditions the data are either …

Correlation Of Cognitive Test Scores And Adequacy Of Treatment In Adolescents With Congenital Hypothyroidism., Mary Lee

Mary M. Lee

PURPOSE: To measure the frequency of noncompliance and its possible effect on school achievement test and cognitive test scores in our older patients with congenital hypothyroidism. METHODS: Fifty patients born from 1976 through 1978 were studied at home when they were 14 years of age. Each patient was given a battery of psychometric and school achievement tests, and blood for hormonal assays was drawn without forewarning from 36 of the patients on the day of examination. Efforts were made to improve control after the second year. During the third summer the tests were repeated in 25 of the 29 patients …

Weak Prezygotic Isolating Mechanisms In Threatened Caribbean Acropora Corals, Nicole Fogarty, Steven Vollmer, Don Levitan

Steve Vollmer

The Caribbean corals, Acropora palmata and A. cervicornis, recently have undergone drastic declines primarily as a result of disease. Previous molecular studies have demonstrated that these species form a hybrid (A. prolifera) that varies in abundance throughout the range of the parental distribution. There is variable unidirectional introgression across loci and sites of A. palmata genes flowing into A. cervicornis. Here we examine the efficacy of prezygotic reproductive isolating mechanisms within these corals including spawning times and choice and no-choice fertilization crosses. We show that these species have subtly different mean but overlapping spawning times, suggesting that temporal isolation is …

Germline Transgenic Methods For Tracking Cells And Testing Gene Function During Regeneration In The Axolotl, Shahryar Khattak, Maritta Schuez, Tobias Richter, Dunja Knapp, Saori Haigo, Tatiana Sandoval-Guzman, Kristyna Hradlikova, Annett Duemmler, Ryan Kerney, Elly Tanaka

Ryan Kerney

The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum (axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent con- trol of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we inducibly …

Mecp2 Binds To Nucleosome Free (Linker Dna) Regions And To H3k9/H3k27 Methylated Nucleosomes In The Brain, Anita Thambirajah, Marlee Ng, Lindsay Frehlick, Andra Li, Jason Serpa, Evgeniy Petrotchenko, Begonia Silva-Moreno, Kristal Missiaen, Christoph Borchers, J. Hall, Ryan Mackie, Frank Lutz, Brent Gowen, Michael Hendzel, Philippe Georgel, Juan Ausio

Philippe T. Georgel

Methyl-CpG-binding protein 2 (MeCP2) is a chromatin-binding protein that mediates transcriptional regulation, and is highly abundant in brain. The nature of its binding to reconstituted templates has been well characterized in vitro. However, its interactions with native chromatin are less understood. Here we show that MeCP2 displays a distinct distribution within fractionated chromatin from various tissues and cell types. Artificially induced global changes in DNA methylation by 3-aminobenzamide or 5-aza-2′-deoxycytidine, do not significantly affect the distribution or amount of MeCP2 in HeLa S3 or 3T3 cells. Most MeCP2 in brain is chromatin-bound and localized within highly nuclease-accessible regions. We also …

Forisome Performance In Artificial Sieve Tubes, Michael Knoblauch, Mike Stubenrauch, Aart J.E. Van Bel, Winfried S. Peters

Winfried S. Peters

Do Larval Traits Re-Evolve? Evidence From The Embryogenesis Of A Direct-Developing Salamander, Plethodon Cinereus, Ryan Kerney, David Blackburn, Hendrik Muller, James Hanken

Ryan Kerney

Recent molecular phylogenies suggest the surprising reacquisition of posthatching metamorphosis within an otherwise directdeveloping clade of lungless salamanders (family Plethodontidae). Metamorphosis was long regarded as plesiomorphic for plethodontids, yet the genus Desmognathus, which primarily includes metamorphosing species, is now nested within a much larger clade of direct-developing species. The extent to which the putative reacquisition of metamorphosis in Desmognathus represents a true evolutionary reversal is contingent upon the extent to which both larva-specific features and metamorphosis were actually lost during the evolution of direct development. In this study we analyze development of the hyobranchial skeleton, which is dramatically remodeled during …

Geometric Constraints And The Anatomical Interpretation Of Twisted Plant Organ Phenotypes, Renate Weizbauer, Winfried S. Peters, Burkhard Schulz

Winfried S. Peters

Intracellular Invasion Of Green Algae In A Salamander Host, Ryan Kerney, Eunsoo Kim, Roger Hangater, Aaron Heiss, Cory Bishop, Brian Hall

Ryan Kerney

The association between embryos of the spotted salamander (Ambystoma maculatum) and green algae (“Oophila amblystomatis” Lamber ex Printz) has been considered an ectosymbiotic mutualism. We show here, however, that this symbiosis is more intimate than previously reported. A combination of imaging and algal 18S rDNA amplification reveals algal invasion of embryonic salamander tissues and cells during development. Algal cells are detectable from embryonic and larval Stages 26–44 through chlorophyll autofluorescence and algal 18S rDNA amplification. Algal cell ultrastructure indicates both degradation and putative encystment during the process of tissue and cellular invasion. Fewer algal cells were detected in later-stage larvae …

Symbioses Between Salamander Embryos And Green Algae, Ryan Kerney

Ryan Kerney

The symbiosis between Ambystoma maculatum (spotted salamander) embryos and green algae was initially described over 120 years ago. Algae populate the egg capsules that surround individual A. maculatum embryos, giving the intracapsular fluid a characteristic green hue. Early work established this symbiosis to be a mutualism, while subsequent studies sought to identify the material benefits of this association to both symbiont and host. These studies have shown that salamander embryos benefit from increased oxygen concentrations provided by their symbiotic algae. The algae, in turn, may benefit from ammonia excreted by the embryos. All of these early studies considered the associ- …

Early Cranial Patterning In The Direct-Developing Frog Eleutherodactylus Coqui Revealed Through Gene Expression, Ryan Kerney, Joshua Gross, James Hanken

Ryan Kerney

Genetic and developmental alterations associated with the evolution of amphibian direct development remain largely unexplored. Specifically, little is known of the underlying expression of skeletal regulatory genes, which may reveal early modifications to cranial ontogeny in direct-developing species. We describe expression patterns of three key skeletal regulators (runx2, sox9, and bmp4) along with the cartilage-dominant collagen 2a1 gene (col2a1) during cranial development in the direct- developing anuran, Eleutherodactylus coqui. Expression patterns of these regulators reveal transient skeletogenic anlagen that correspond to larval cartilages, but which never fully form in E. coqui. Suprarostral anlagen in the frontonasal processes are detected through …

My Embarrassment At Not Knowing Heinich, Winfried S. Peters

Winfried S. Peters

Life History, Sexual Dimorphism And 'Ornamental' Feathers In The Mesozoic Bird Confuciusornis Sanctus., Winfried S. Peters, Dieter Stefan Peters

Winfried S. Peters

Gfp Tagging Of Sieve Element Occlusion (Seo) Proteins Results In Green Fluorescent Forisomes, Hélène Pélissier, Winfried Peters, Ray Collier, Aart Van Bel, Michael Knoblauch

Winfried S. Peters

Gene Expression Reveals Unique Skeletal Patterning In The Limb Of The Direct-Developing Frog, Eleutherodactylus Coqui, Ryan Kerney, James Hanken

Ryan Kerney

The growing field of skeletal developmental biology provides new molecular markers for the cellular pre- cursors of cartilage and bone. These markers enable resolution of early features of skeletal development that are otherwise undetectable through conventional staining tech- niques. This study investigates mRNA distributions of skeletal regulators runx2 and sox9 along with the cartilage-dominant collagen 2a1 (col2a1) in embryonic limbs of the direct- developing anuran, Eleutherodactylus coqui. To date, distri- butions of these genes in the limb have only been examined in studies of the two primary amniote models, mouse and chicken. In E. coqui, expression of transcription factors runx2 …

The Regulation Of Genes And Genomes By Small Rnas., Victor Ambros, Xuemei Chen

Victor R. Ambros

A recent Keystone Symposium on 'MicroRNAs and siRNAs: Biological Functions and Mechanisms' was organized by David Bartel and Shiv Grewal (and was held in conjunction with 'RNAi for Target Validation and as a Therapeutic', organized by Stephen Friend and John Maraganore). The 'MicroRNAs and siRNAs' meeting brought together scientists working on diverse biological aspects of small regulatory RNAs, including microRNAs, small interfering RNAs (siRNAs) and Piwi-interacting RNAs (piRNAs and rasiRNAs). Among the themes discussed were the diversity of small regulatory RNAs and their developmental functions, their biogenesis, the identification of their regulatory targets, their mechanisms of action, and their roles …

Potent Effect Of Target Structure On Microrna Function, Peter Williams, Dang Long, Rosalind Lee, Chi Chan, Victor Ambros, Ye Ding

Victor R. Ambros

MicroRNAs (miRNAs) are small noncoding RNAs that repress protein synthesis by binding to target messenger RNAs. We investigated the effect of target secondary structure on the efficacy of repression by miRNAs. Using structures predicted by the Sfold program, we model the interaction between an miRNA and a target as a two-step hybridization reaction: nucleation at an accessible target site followed by hybrid elongation to disrupt local target secondary structure and form the complete miRNA-target duplex. This model accurately accounts for the sensitivity to repression by let-7 of various mutant forms of the Caenorhabditis elegans lin-41 3' untranslated region and for …

Characterization Of Microrna Expression Levels And Their Biological Correlates In Human Cancer Cell Lines., Caifu Chen, Arti Gaur, David Jewell, Yu Liang, Dana Ridzon, Jason Moore, Victor Ambros, Mark Israel

Victor R. Ambros

MicroRNAs are small noncoding RNAs that function by regulating target gene expression posttranscriptionally. They play a critical role in developmental and physiologic processes and are implicated in the pathogenesis of several human diseases including cancer. We examined the expression profiles of 241 human microRNAs in normal tissues and the NCI-60 panel of human tumor-derived cell lines. To quantify microRNA expression, we employed a highly sensitive technique that uses stem-loop primers for reverse transcription followed by real-time PCR. Most microRNAs were expressed at lower levels in tumor-derived cell lines compared with the corresponding normal tissue. Agglomerative hierarchical clustering analysis of microRNA …

The 2007 George W. Beadle Medal. Robert K. Herman., Victor Ambros

Victor R. Ambros

No abstract provided.

Runx2 Is Essential For Larval Hyobranchial Cartilage Formation In Xenopus Laevis, Ryan Kerney, Joshua Gross, James Hanken

Ryan Kerney

The vertebrate transcription factor protein Runx2 is regarded as a “master regulator” of bone formation due to the dramatic loss of the osseous skeleton in the mouse homozygous knockout. However, Runx2 mRNA also is expressed in the pre-hypertrophic cartilaginous skeleton of the mouse and chicken, where its developmental function is largely unknown. Several tiers of Runx2 regulation exist in the mouse, any of which may account for its seeming biological inactivity during early stages of skeletogenesis. Unlike mouse and chicken, zebrafish require Runx2 function in early cartilage differentiation. The present study reveals that the earlier functional role of Runx2 in …