The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry最新文献

{"title":"Sry promoters from domesticus (Tirano) and C57BL/6 mice function similarly in embryos and adult animals.","authors":"M. Xian, J. Zhang, Y. Lau","doi":"10.1002/JEZ.1114","DOIUrl":"https://doi.org/10.1002/JEZ.1114","url":null,"abstract":"Introduction of the Y chromosome from a Mus musculus domesticus (Tirano) subspecies into the Mus musculus musculus C57BL/6 (B6) inbred strain background results in sex reversal in XY offspring. It has been hypothesized that the domesticus testis-determining Y (Tdy) locus is misregulated in B6 genome, thereby impairing sex determination in B6.Y(Dom) animals. The identification of a gene in the sex-determining region on the Y chromosome (Sry) as the Tdy has provided a means to experimentally examine this hypothesis. We have generated several lines of B6 transgenic mice harboring a green fluorescent protein gene directed by a Sry promoter from the domesticus (Tirano) Y chromosome. Detailed analysis of the transgene expression was conducted in both fetal and adult tissues of the transgenic mice. The domesticus Sry promoter was capable of directing the expression of the green fluorescent protein gene in a pattern similar, if not identical, to that of the endogenous B6 Sry gene. These observations suggest that the domesticus Sry promoter is not involved in the postulated misregulation of the domesticus (Tirano) Sry gene in the B6 genomic background. These results are discussed with reference to a second hypothesis invoking incompatible protein interaction(s) as a mechanism of aberrant sex determination in B6.Y(Dom) animals.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"21 1","pages":"632-41"},"PeriodicalIF":0.0,"publicationDate":"2001-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75567497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glucagon effects on brain carbohydrate and ketone body metabolism of rainbow trout.","authors":"L. Magnoni, J. Míguez, J. Soengas","doi":"10.1002/JEZ.1117","DOIUrl":"https://doi.org/10.1002/JEZ.1117","url":null,"abstract":"The levels of glycogen in brain, lactate and acetoacetate in brain and plasma, glucose in plasma and the activities of brain key enzymes of glycogen metabolism (glycogen phosphorylase, GPase, glycogen synthetase, GSase), gluconeogenesis (fructose 1,6-bisphosphatase, FBPase), and glycolysis (6-phosphofructo 1-kinase, PFK) were evaluated in rainbow trout, Oncorhynchus mykiss, from 0.5 to 3 hr after intraperitoneal injection of 1 ml/kg(-1) body weight of saline alone (controls) or containing bovine glucagon at three different doses: 10, 50, and 100 ng/g(-1) body weight. The results obtained demonstrate, for the first time in a teleost fish, the existence of changes in brain carbohydrate and ketone body metabolism following peripheral glucagon treatment. A clear stimulation of brain glycogenolytic potential was observed after glucagon treatment, as judged by the time- and dose-dependent changes observed in brain glycogen levels (up to 88% decrease), and GPase (up to 30% increase) and GSase (up to 42% decrease) activities. In addition, clear time- and dose-dependent increased and decreased levels were observed in brain of glucagon-treated rainbow trout for lactate (up to 60% increase) and acetoacetate (up to 67% decrease), respectively. In contrast, no significant changes were observed after glucagon treatment in those parameters related to glycolytic/gluconeogenic capacity of rainbow trout brain. Altogether, these in vivo results suggest that glucagon may play a role (direct or indirect) in the regulation of carbohydrate and ketone body metabolism in brain of rainbow trout.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"1 1","pages":"662-71"},"PeriodicalIF":0.0,"publicationDate":"2001-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82756653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wnts and the female reproductive system.","authors":"M. Heikkilä, H. Peltoketo, S. Vainio","doi":"10.1002/JEZ.1112","DOIUrl":"https://doi.org/10.1002/JEZ.1112","url":null,"abstract":"Wnts are intercellular growth and differentiation factors that regulate several key developmental steps, such as gastrulation, neurulation, and organogenesis, including the development of the midbrain, central nervous system, kidney, and limbs. Wnts are also needed for a normal development of the reproductive system. Deficiency of Wnt-4, -5a, and -7a, for example, results in sex reversal, infertility, and/or malformation of the internal and external genitals. Here we focus on the importance of Wnts in the female reproductive system.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"15 1","pages":"616-23"},"PeriodicalIF":0.0,"publicationDate":"2001-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80693079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Altered timing of the extracellular-matrix-mediated epithelial-mesenchymal interaction that initiates mandibular skeletogenesis in three inbred strains of mice: development, heterochrony, and evolutionary change in morphology.","authors":"M. Macdonald, B. Hall","doi":"10.1002/JEZ.1102.ABS","DOIUrl":"https://doi.org/10.1002/JEZ.1102.ABS","url":null,"abstract":"Subtle changes in embryonic development are a source of significant morphological alterations during evolution. The mammalian mandibular skeleton, which originates from the cranial neural crest, is a complex structure comprising several components that interact late in embryogenesis to produce a single functional unit. It provides a model system in which individual developmental events at the basis of population-level evolutionary change can be investigated experimentally. Inbred mouse strains exhibit obvious morphological differences despite the relatively short time since their divergence from one another. Some of these differences can be traced to small changes in the timing of early developmental events such as the formation of the cellular condensations that initiate skeletogenesis. This paper examines an even earlier event for changes in timing, the epithelial-mesenchymal interaction(s) required to initiate chondrogenesis of Meckel's cartilage and osteogenesis of the dentary bone. Using three inbred strains of mice (CBA, C3H and C57) we found that, within each strain, cartilage and bone are induced at the same time and by the same (mandibular) epithelium, that chondrogenesis and osteogenesis are initiated by a matrix-mediated epithelial-mesenchymal interaction, and that timing of the interactions differs among the three inbred strains. These results are discussed with respect to the possible molecular basis of such temporal shifts in inductive interactions and how such studies can be used to shed light on heterochrony as a mechanism of evolutionary change in morphology.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"2 1","pages":"258-73"},"PeriodicalIF":0.0,"publicationDate":"2001-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83608170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The tetrapod limb: a hypothesis on its origin.","authors":"G. Wagner, C. Chiu","doi":"10.1002/JEZ.1100","DOIUrl":"https://doi.org/10.1002/JEZ.1100","url":null,"abstract":"A wrist joint and structures typical of the hand, such as digits, however, are absent in [Eustenopteron] (Andrews and Westoll, '68, p 240). Great changes must have been undergone during evolution of the ankle joint; the small number of large bones in the fin must somehow have developed into a large number of small bones, and it is very difficult to draw homologies in this region, or even be certain of what is being compared (Andrews and Westoll, '68, p 268). The tetrapod limb is one of the major morphological adaptations that facilitated the transition from an aquatic to a terrestrial lifestyle in vertebrate evolution. We review the paleontological evidence for the fin-limb transition and conclude that the innovation associated with evolution of the tetrapod limb is the zeugopodial-mesopodial transition, i.e., the evolution of the developmental mechanism that differentiates the distal parts of the limb (the autopodium, i.e., hand or foot) from the proximal parts. Based on a review of tetrapod limb and fish fin development, we propose a genetic hypothesis for the origin of the autopodium. In tetrapods the genes Hoxa-11 and Hoxa-13 have locally exclusive expression domains along the proximal-distal axis of the limb bud. The junction between the distal limit of Hoxa-11 expression and of the proximal limit of Hoxa-13 expression is involved in establishing the border between the zeugopodial and autopodial anlagen. In zebrafish, the expression domains of these genes are overlapping and there is no evidence for an autopodial equivalent in the fin skeleton. We propose that the evolution of the derived expression patterns of Hoxa-11 and Hoxa-13 may be causally involved in the origin of the tetrapod limb.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"32 1","pages":"226-40"},"PeriodicalIF":0.0,"publicationDate":"2001-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73655722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulation of male sexual development by Sry and Sox9.","authors":"P. Koopman, M. Bullejos, J. Bowles","doi":"10.1002/JEZ.1089","DOIUrl":"https://doi.org/10.1002/JEZ.1089","url":null,"abstract":"Sry, a gene from the Y chromosome, is known to initiate testis formation and subsequent male differentiation in mammals. A related gene, Sox9, also plays a critical role in testis determination, possibly in all vertebrates. A number of models have been presented regarding the molecular modes of action of these two genes. However, details regarding their regulation, regulatory target genes, and interacting protein factors and co-factors have not been established with any certainty. In this review, we examine new evidence and re-examine existing evidence bearing on these issues, in an effort to build up an integrative model of the network of gene activity centred around Sry and Sox9. J. Exp. Zool. 290:463-474, 2001.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"48 1","pages":"463-74"},"PeriodicalIF":0.0,"publicationDate":"2001-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81609796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex reversal and aromatase in the European pond turtle: treatment with letrozole after the thermosensitive period for sex determination.","authors":"B. Belaid, N. Richard-Mercier, C. Pieau, M. Dorizzi","doi":"10.1002/JEZ.1092","DOIUrl":"https://doi.org/10.1002/JEZ.1092","url":null,"abstract":"In the European pond turtle (Emys orbicularis), gonadal sex differentiation is temperature-dependent. The temperature sensitive period (TSP) of gonadogenesis lies between stages 16 and 22 of embryonic development. Previous studies have shown that embryos incubated at 30 degrees C, a temperature yielding 100% phenotypic females, can be sex reversed by treatments with an aromatase inhibitor administered during TSP or even somewhat after TSP (as of stage 22+). The goal of the present study was to determine whether the ovary still retains male potential at later stages of embryonic development and whether the induced male characters persist after hatching. For this purpose, eggs of E. orbicularis were treated with letrozole, a nonsteroidal aromatase inhibitor, at or as of stages 23, 24 or 25, then gonadal aromatase activity in each individual and the related gonadal structure were studied at hatching (stage 26) and for one year after hatching. Two kinds of treatments were carried out: 1) repeated applications of 10 microg of letrozole in ethanolic solution onto the eggshell; and 2) a single injection of 10 microg of letrozole in olive oil. Similar results were obtained with either application or injection of the aromatase inhibitor. In treatments as of or at stage 23, individuals with gonadal aromatase activity lower than 20 fmoles/hour/gonad had ovotestes, i.e., 22% of the treated individuals. At hatching, the inner part of these ovotestes contained testicular cords and also mixed lacunae presenting various degrees of transdifferentiation of the epithelium into a Sertolian epithelium. The cortex was maintained, although some germ cells degenerated within it. These processes continued after hatching. However, at 12 months, gonads were still ovotestes displaying some follicles with a growing oocyte in the remaining parts of the cortex. In treatments as of or at stages 24 or 25, only a few individuals were masculinized. One had ovotestes; in others, the cortex was absent in some parts and when it was present oocytes were degenerating. These results show that in the European pond turtle, differentiation of ovotestes from ovaries can be induced by treatment with an aromatase inhibitor starting at late stages of embryonic development (between the end of TSP and hatching), although such differentiation is less frequent as embryonic development proceeds. Sex reversal persists for at least one year after hatching. J. Exp. Zool. 290:490-497, 2001.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"30 1","pages":"490-7"},"PeriodicalIF":0.0,"publicationDate":"2001-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77994615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex from W to Z: evolution of vertebrate sex chromosomes and sex determining genes.","authors":"J. Graves, S. Shetty","doi":"10.1002/JEZ.1088","DOIUrl":"https://doi.org/10.1002/JEZ.1088","url":null,"abstract":"Sex determination in major vertebrate groups appears to be very variable, including systems of male heterogamety, female heterogamety and a variety of genetic and environmental sex determining systems. Yet comparative studies of sex chromosomes and sex determining genes now suggest that these differences are more apparent than real. The sex chromosomes of even widely divergent groups now appear to have changed very little over the last 300+ million years, and even independently derived sex chromosomes seem to have followed the same set of evolutionary rules. The sex determining pathway seems to be extremely conserved, although the control of the genes in this pathway is vested in different elements. We present a scenario for the independent evolution of XY male heterogamety in mammals and ZW female heterogamety in birds and some reptiles. We suggest that sex determining genes can be made redundant, and replaced by control at another step of a conserved sex determining pathway, and how choice of a gene as a sex switch has led to the evolution of new sex chromosome systems. J. Exp. Zool. 290:449-462, 2001.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"33 1","pages":"449-62"},"PeriodicalIF":0.0,"publicationDate":"2001-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86754762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and regulatory macromolecules in sex differentiation of gonads.","authors":"L. Pelliniemi, K. Fröjdman","doi":"10.1002/JEZ.1096","DOIUrl":"https://doi.org/10.1002/JEZ.1096","url":null,"abstract":"The manifestations of sex determination were studied in vivo by detection and localization of structural and regulatory macromolecules (type IV collagen alpha 1, alpha 2, alpha 3, alpha 4, and alpha 5; laminin alpha 5, beta 1, and beta 2; cytokeratins 18 and 19, desmin, vimentin; integrin alpha(6;) anti-Müllerian hormone (AMH); and SOX9 in developing male and female gonads by light and electron microscopy, immunocytochemistry, and protein analysis. The goal has been to find sex-related differences and on this basis to offer new molecules to be tested further for a possible role in sex determination. Specific antibodies for each molecule or for a defined subchain were used to allow tentative correlation with specific genes. Sex-dependent differences in timing and localization were found in laminin alpha 5; collagen, alpha 3, alpha 4, and alpha 5; cytokeratin 19; AMH; and SOX9. On this basis we hypothesize that the transcription factors for the mentioned structural proteins must be directly or indirectly involved in the regulatory chain of gonadal sex differentiation. Especially promising is the finding in the rat that laminin alpha 5 chain disappears from the basement membrane of embryonic testicular cords (Sertoli cells) when AMH secretion by Sertoli cells starts, and that the same chain reappears as the AMH disappears two weeks after birth. Via AMH as an intermediary factor, we now have for the first time a putative cascade of regulatory molecules from SRY, SF1, and SOX9 to a component of a structural protein (laminin alpha 5 chain) which directly participates in the formation of the basement membrane of the testicular cords. J. Exp. Zool. 290:523-528, 2001.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"89 1","pages":"523-8"},"PeriodicalIF":0.0,"publicationDate":"2001-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80362197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Persistence of oviposition rhythm in individuals of Drosophila melanogaster reared in an aperiodic environment for several hundred generations.","authors":"V. Sheeba, M. Chandrashekaran, A. Joshi, V. K. Sharma","doi":"10.1002/JEZ.1098","DOIUrl":"https://doi.org/10.1002/JEZ.1098","url":null,"abstract":"The oviposition rhythm of individual flies of Drosophila melanogaster from a population maintained in an aperiodic environment (with light, temperature, humidity, and other factors which could provide time cues, kept constant) for several hundred generations was assayed in constant light (LL), in light/dark (LD 12:12 hr) cycle, and in constant darkness (DD). More than 50% of the flies assayed exhibited rhythmicity in oviposition in all three light regimes. The results indicate that the phenomenon of egg laying is rhythmic in individual D. melanogaster females and is controlled by an endogenous time keeping mechanism. The persistence of the oviposition rhythm in a large proportion of individuals in the population after several hundred generations of rearing in a constant environment strengthens the view that possessing biological clocks may confer some intrinsic fitness advantage even to organisms living in aperiodic environments. J. Exp. Zool. 290:541-549, 2001.","PeriodicalId":77637,"journal":{"name":"The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry","volume":"65 2 1","pages":"541-9"},"PeriodicalIF":0.0,"publicationDate":"2001-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80771688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}