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CHROMOSOMAL SEX DETERMINATION & HUMAN Y CHROMOSONE.   Term Paper ID:28997 Click to get this paper Essay Subject: Scientific discussion of genetic material of & Chromosone.... More... 7 Pages / 1575 Words 23 sources, 27 Citations, APA Format $28.00 Return to List of Papers Paper Abstract: Scientific discussion of genetic material of Y Chromosone. Research on human genetics. Concept of sexual selection. Male & female traits. Genes on the Y Chromosone. & their crucial role. Implications of mechanisims of chromosomal sex determination. Paper Introduction: Review of Functional Coherence of the Human Y Chromosome Introduction In the current rush to map the human genome it is sometimes easy to assume that the modern science of genetics understands all there is to know concerning the functions of the human Y chromosome. This is far from reality. Because there has been such tremendous effort for an extended period of time on molecular biology, i.e.; research into AIDS, cancer, and auto immune diseases, certain aspects of human genetics have been underexplored. This no longer is the case. The article by Lahn and Page make some salient points: the wasteland model of Y chromosome content was based largely on anectodotal evidence (Lahn and Page, 1997, p 676); at Text of the Paper: The entire text of the paper is shown below. However, the text is somewhat scrambled. We want to give you as much information as we possibly can about our papers and essays, but we cannot give them away for free. In the text below you will find that while disordered, many of the phrases are essentially intact. From this text you will be able to get a solid sense of the writing style, the concepts addressed, and the sources used in the research paper. is to knowconcerning the functions of immune diseases certain aspects of human genetics anectodotal evidence Lahn and Page similar but nonidentical protein isoform every and Page drew their genetic housekeeping as suggested by their ubiquitous expression and by Nachmais E FA Y encodes a Y isoform was a wastelandcarrying no genetic information apart from the region which constitutes about of thehuman genes that have been identified in this only in the testis thought to be involvedin the the Y chromosome not seen in autosomes chromosome that enhance malefertilization success the evolution of traits that confer advantages incompetition over by making a male attractiveto females Male-male competition in male contests includeweapons such as horns antlers and but also an intense effort to develop mathematical and accessto high quality territories However the but the nature of such fertilized bysuperior males D other authors believe that rolein the control of proliferation and or differentiation of the totalabsence of spermatozoa in the ejaculate cells atcrucial stages of spermatogenesis D or N Salido E C and Yen P H This has population would have Ychromosomes with a different number of copies there a relationship between the demonstrated include several that might also beimportant in sexual counterparts at thesame gestational age reflected in the number a region controllingstature Ogata T and Matsuo N of the human Y chromosome above Erickson R P Measurements enamel anddentinogenesis i e the growth of dentine development is promoted by a genes are functionally unique becauseX with deletions in the regioncontaining this testis Lahn andPage More genes might be discovered be found on the Y two species Just W et al is sex to accumulate genes that arebeneficial to such genes passon through the begun touncover how this process works References Alvesalo The mammalian Y chromosome a new perspective BioEssays Chai N Does sex determination start at conception BioEssays Fignee E M in sperm tails HumanReproduction Hershey J W Nature Lahn B T and Page D C embryonic development and pregnancy occur when retrieved testicularspermatozoa are used J L et al Microdeletions al Deletion mapping of stature determinants on International Workshop onY Chromosome Mapping Cytogenet Cell Genet and Zeh D W The evolution of polyandry I human genome it is sometimes easy toassume that the modern effort for an extendedperiod of time on molecular biology Page makesome salient points the wasteland model of Y chromosome chromosome Accordingly each gene found has a homolog on exist in a single copy on the Manyof the X-homologous genes appear Y encodesa Y isoform of thymosin which functions protein Fignee E M For many there areactually more than genes or gene families in the seen between homologousautosomes and between the pseudoautosomal regions of the high degree of homology to genes et al The existence of these Y-specificgenes involved in the inmale-male contests and in sperm competition Therefore sexual selectioncould Research The concept of sexual selection vis-a-vis Such traits enhance reproductive success either by improving amale's ability has not been the focus of muchempirical research has been a controversial subject Reluctance to accept the such choices remain to beexplained In somecases females gain direct J A and Zeh D W population will differ in theirintrinsic genes on the human Y chromosome expressed exclusively inthe two sets of data First patients with a defective sperm L et al Second products of these is that they occur in multiple would not completely block spermatogenesis MulhallJ P et al P H Chai N N individuals Future Research Directions Other genes on the Y chromosome species XY embryos grow faster than XX ones The has been shown to persist to mid-gestation It has on stature has been identified inthe gene is different from the have suggested that the Y chromosome influences in size shape and number of teeth the X chromosome Salido E C et al AMLX It is possible that GCY is has been guided by theassumption that they would brain Burgoyne P S Further searches would benefit from conservation across mammals including marsupials The best example is the et al Conclusion In conclusion Inmammals such genes spread through the male line and battle of the sexes there seems to belittle the homogametic University Press Brown J L A theory of mate choice family a spermatogenesis candidate on the al DAZ Deleted in AZoospermia genes encodeproteins Genetics Kempenaers B et al Extra-pair paternity al Azoospermic men with deletion of the DAZgene cluster stature deduction of the principal factors involved protein gene amelogenin isexpressed from both the X and the of BiologicalChemistry p Vol Vogt P H et male infertility factor on the Y chromosome are highlypolymorphic Review of Functional Coherence of the the human Y chromosome This is have been under-explored This no longer is the case p at least novel genes can be identified gene found is expressed in a material from the testis thegene pairs uncovered seem to the functions of theencoded proteins which of elf A anessential translation initiation factor Hershey RPS Y sex-determining gene SRY The work of Lahn and Y chromosome does not exchange genetic material with the Xchromosome region ofthe Y chromosome fall control of spermatogenesis and that are only which carrygenes with no common function Lahn and because they spread unaltered through the mates often at the expense was intuitively accepted as an importantprocess enlarged canines and large body models Although the available evidence supports the benefits in other cases remainobscure particularly genetic quality remains elusive Whereas some it is the degree of geneticcompatibility between a male and male germline to form spermatozoa Their azoospermia have microdeletionsin regions of the Y chromosome in mature spermatozoa HabermannB et al One important characteristic common three implications First gene copies might act together increasing of each gene or withdifferent sequence repeats' or even numberof copies of genes controlling spermatogenesis in different individuals selection such as those related to the control ofembryonic of blastomeres or somites weight body length and head size A putative gene named GrowthControl Salo P et al It of enamel and dentine thickness of permanent incisors andcanines in Alvesalo L The effectof the Y chromosome on gene on the Ychromosome AMELY inactivation can act on the X locus putative gene also have smaller teeth Salo P etal The on the Y chromosome ifexpression products are looked chromosome One important feature of the genes on the Y present in allmammalian species studied so far that sex even at the female line and are predicted to be related to L Sex chromosomes and human N Salido E C and Yen P H Cell p Vol Fisher R A Biological Annual Review of Biochemistry p Just W et al Absence October Functional Coherence ofthe Human Y Chromosome pp Science for intracytoplasmic sperm injection HumanReproduction Ogata T and Matsuo in the Y chromosome ofinfertile men New England Journal of thelong arm of the Y chromosome Human Genetics Sater D Yen P H Chai N N and Salido intragenomic conflict and genetic incompatibility Proc science of genetics understands all there i e research into AIDS cancer andauto content was based largely on the X chromosome encoding a very NRY Lahn and Page p Further Results Because Lahn to be involved in cellular in actin sequestration Sater Elzinga years it was assumed that the Y chromosome nonrecombining regionof the human Y chromosome This X and Ychromosomes Vogt P H As mentioned the present on the Xchromosome and genes expressed control of spermatogenesis indicate a uniquefunctional coherence of have favored genes on the Y X and Y chromosomes wasdeveloped to explain to win intrasexual contests or Traits assumed to be important theory has prompted not only numerous empiricalstudies benefits such as food paternal care One particularly controversial hypothesis proposes that females lookfor good genes' genetic quality and that females should aim to be testes Lahn and Page These genes probably play a crucial productionand therefore a reduced sperm number severe oligospermia or a genes have been found in germ copies and can bepolymorphic in their sequences Chai N Third different males in a and Salido E C Thisleads to the following question is whose presence has been eitherinferred or actually XY individualsare also developmentally more advanced than their XX been proposed that the Y chromosome has most proximal region of the long arm genedetermining the Y-effect on embryo growth Growth factor Y described dentalgrowth by promoting both amelogenesis i e the growth of Alvesalo L Growthof tooth buds during human transcripts are more abundant than theAMELY ones However the AMELX-AMELY also involved intooth development because individuals be found preferentially in the clearpredictions as to which genes are likely to testis-determining gene SRY that with theexception of mechanisms of chromosomal sex determination provide anopportunity for the heterogametic are related toejaculate quality and competitive ability whereas in birds sex can do The work of Lahn and Page has based on heterozygosity Behavioral Ecology Burgoyne P S human Ychromosome Genomics Erickson R P located in human late spermatids and results from femalepreference for high-quality males in the blue tit are capable of completing spermatogenesis fertilization normal in the determination of adultheight Human Genetics Pryor Y chromosomes American Journal of HumanGenetics Salo P et al Report of the Third in the DAZ repeat regions Mammalian Genome Zeh J A Human Y ChromosomeIntroduction In the current rush to map the far fromreality Because there has been such tremendous The article by Lahn and from the non-recombinant NRY portion of the Y wide range of human tissues and each gene appears to express themselves primarily in testis are well established in three cases TB encodes a Yisform of an essential ribosomal Page among others has revealed that in contrast to the recombination into two categories genes that are ubiquitouslyexpressed and with a present on the Ychromosome Kempenaers B Page Among mammals these traits influence a male's competitive ability male line Fisher Significance of of survival rates Andersson M and perhaps for this reason size In contrast female choice view that females activelychoose their sexual partners the implications of when females receive little more than sperm frommales Zeh authors argue that males in a a female that matters Brown J L There are ten involvement in spermatogenesis is deducedfrom carrying these genes Pryor J to all the testis-specific geneson the Y chromosome the efficiency' of spermatogenesis Second deletions ormutations in one copy different combinations of copynumbers and sequences Yen andthe number of sperm or sperm abnormalities in those growth stature and the development of teeth In severalmammalian Erickson R P This GrowthFactor Y-effect Y GCY with a marked effect is likely that this GCY normal females and males and in individuals with sex-chromosomeabnormalities tooth growth could explain the expression of sexualdimorphism and an homologous gene AMELX on so that males have potentially moregene product than do females search for products of gene expression for in other tissues such as chromosome is that theyshow a high degree of although interestingly its sequence isnot highly conserved Vogt P H expense of the homogametic sex the abilityto choose male handicaps In this growth A dentalapproach Human Genetics Andersson M Sexual Selection Princeton Multiple functional copiesof the RBM gene Review p Habermann B et of Sry in species of the vole Ellobius Natural Vol Mulhall J P et N Sex chromosome aberrations and Medicine Salido E C et al The human enamel Elzinga M Nachmai V T Journal E C The human DAZ genes aputative R Soc London Ser B is to knowconcerning the functions of immune diseases certain aspects of human genetics anectodotal evidence Lahn and Page similar but nonidentical protein isoform every and Page drew their genetic housekeeping as suggested by their ubiquitous expression and by Nachmais E FA Y encodes a Y isoform was a wastelandcarrying no genetic information apart from the region which constitutes about of thehuman genes that have been identified in this only in the testis thought to be involvedin the the Y chromosome not seen in autosomes chromosome that enhance malefertilization success the evolution of traits that confer advantages incompetition over by making a male attractiveto females Male-male competition in male contests includeweapons such as horns antlers and but also an intense effort to develop mathematical and accessto high quality territories However the but the nature of such fertilized bysuperior males D other authors believe that rolein the control of proliferation and or differentiation of the totalabsence of spermatozoa in the ejaculate cells atcrucial stages of spermatogenesis D or N Salido E C and Yen P H This has population would have Ychromosomes with a different number of copies there a relationship between the demonstrated include several that might also beimportant in sexual counterparts at thesame gestational age reflected in the number a region controllingstature Ogata T and Matsuo N of the human Y chromosome above Erickson R P Measurements enamel anddentinogenesis i e the growth of dentine development is promoted by a genes are functionally unique becauseX with deletions in the regioncontaining this testis Lahn andPage More genes might be discovered be found on the Y two species Just W et al is sex to accumulate genes that arebeneficial to such genes passon through the begun touncover how this process works References Alvesalo The mammalian Y chromosome a new perspective BioEssays Chai N Does sex determination start at conception BioEssays Fignee E M in sperm tails HumanReproduction Hershey J W Nature Lahn B T and Page D C embryonic development and pregnancy occur when retrieved testicularspermatozoa are used J L et al Microdeletions al Deletion mapping of stature determinants on International Workshop onY Chromosome Mapping Cytogenet Cell Genet and Zeh D W The evolution of polyandry I human genome it is sometimes easy toassume that the modern effort for an extendedperiod of time on molecular biology Page makesome salient points the wasteland model of Y chromosome chromosome Accordingly each gene found has a homolog on exist in a single copy on the Manyof the X-homologous genes appear Y encodesa Y isoform of thymosin which functions protein Fignee E M For many there areactually more than genes or gene families in the seen between homologousautosomes and between the pseudoautosomal regions of the high degree of homology to genes et al The existence of these Y-specificgenes involved in the inmale-male contests and in sperm competition Therefore sexual selectioncould Research The concept of sexual selection vis-a-vis Such traits enhance reproductive success either by improving amale's ability has not been the focus of muchempirical research has been a controversial subject Reluctance to accept the such choices remain to beexplained In somecases females gain direct J A and Zeh D W population will differ in theirintrinsic genes on the human Y chromosome expressed exclusively inthe two sets of data First patients with a defective sperm L et al Second products of these is that they occur in multiple would not completely block spermatogenesis MulhallJ P et al P H Chai N N individuals Future Research Directions Other genes on the Y chromosome species XY embryos grow faster than XX ones The has been shown to persist to mid-gestation It has on stature has been identified inthe gene is different from the have suggested that the Y chromosome influences in size shape and number of teeth the X chromosome Salido E C et al AMLX It is possible that GCY is has been guided by theassumption that they would brain Burgoyne P S Further searches would benefit from conservation across mammals including marsupials The best example is the et al Conclusion In conclusion Inmammals such genes spread through the male line and battle of the sexes there seems to belittle the homogametic University Press Brown J L A theory of mate choice family a spermatogenesis candidate on the al DAZ Deleted in AZoospermia genes encodeproteins Genetics Kempenaers B et al Extra-pair paternity al Azoospermic men with deletion of the DAZgene cluster stature deduction of the principal factors involved protein gene amelogenin isexpressed from both the X and the of BiologicalChemistry p Vol Vogt P H et male infertility factor on the Y chromosome are highlypolymorphic If this paper is not what you are 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