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Non-Homologous Chromosome Synapsis During Mouse Meiosis

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Non-Homologous Chromosome Synapsis During Mouse Meiosis Non-homologous chromosome synapsis during mousemeiosis : consequences for malefertilit y and survival ofprogeny . Niet-homologechromosoo m synapsistijden s demeios eva n demuis : gevolgen voormannelijk e vruchtbaarheid enoverlevin g van nageslacht. Promoter: dr. C.Heytin g Hoogleraar ind eMoleculair e en Celgenetica Co-promoter: dr. ir.P .d eBoe r Universitair hoofddocent bij het departement Biomoleculaire Wetenschappen, laboratorium voor Erfelijkheidsleer /v/tfoS?0* ) 2.3VG Non-homologous chromosome synapsis during mousemeiosis : consequences for malefertilit y and survival ofprogen y Antoine Hendrik Felix MariePeter s Proefschrift ter verkrijging van degraa d van doctor opgeza gva n derecto r magnificus van d \andbouwuniversiteit Wageningen, dr. CM. Karssen, i ^topenbaa r te verdedigen opvi ^ "o2 1novembe r 1997 des namiddags ^alftwe e in deAula . CIP-Data Koninklijke Bibliotheek, Den Haag Peters,Antoin eHendri kFeli xMari e Non-homologouschromosom e synapsisdurin gmous emeiosis :consequence s formal efertilit y andsurviva lo f progeny/ Antoin eHendri kFeli xMari ePeters .- [S.I.:s.n.] .- II1 ThesisLandbouwuniversitei t Wageningen.- Wit href . - Withsummar yi nDutc han dGerman . ISBN:90-5485-776- 5 Subject headings:meiosi s/ synapsi s/ mutatio n/ mous e BIBIJOTHEFK LANDFO^rWUNIVERSrraT WAGEMNTFM Stellingen 1. Chromosomen hebbenme t betrekking tot hun synaptisch gedrag een geheugen. Dit proefschrift 2. Homo- of heterozygotie voor de Robertsonische translocatie Rb(11.13)4Bnr (Rb4) heeft niet altijd een reducerend effect op de mannelijke vruchtbaarheid. Afhankelijk van de overige in het karyotype aanwezige chromosoomafwijkingen kanRb 4 ook stimulerend werken. Dit proefschrift 3. Niet-homologe chromosoom synapsis in afwezigheid van meiotische recombinatie leidt niet tot dominante of recessieve vormen van chromosoom instabiliteit. In aanwezigheid van recombinatie mogelijk wel. Dit proefschrift 4. Klassieke chromosoom mutanten kunnen een vergrootglas funktie vervullen bij meiotisch cytologisch onderzoek. Plug etal., Natur e Genetics, inpres s 5. Publiceerbaarheid van gegevens bepaalt niet alleen het plezier in wetenschappelijk onderzoek. Het kan dit wel versterken. 6. Moleculair biologen leven inzwart/wit , cytologen inkleur . 7. Sonore koorzang ishe t zoeken naar harmonie tussen het individu enhe t collectief. 8. Helaas zijn veel (vooraanstaande) wetenschappers geen goede koorzangers. 9. Nalatige hooggeplaatsten zijn ware alchemisten: het lukt henvaa k het vuil aan hun handen omt e zetten ingoud . 10. Email maakt onmogelijke relaties mogelijk. 11. Het betere isd evijan d vanhe t goede. Stellingen behorende bij het proefschrift "Non-homologous chromosome synapsis during mousemeiosis : consequences for malefertilit y and survival ofprogeny " Wageningen, 21 november 1997 AntoineH.F.M . Peters Voormijn vader Contents Chapter Page 1 General introduction 1 2 A drying-down technique for spreading of mammalian meiocytes from the 15 malean d female germline. 3 Meiosis in carriers of heteromorphic bivalents: sex differences and 21 implications for male fertility. 4 Chromosomal assignment ofth emicrosatellite s DlMit4, -52,-20 , -121, -122 39 and thecollage n locus(Col9al ) distal from theT(1;13)70 H breakpoint ando f the loci for the crystallin protein (Cryg), the cAMP responsive element binding protein (Crebl) andth emyosi n light chainprotei n (Mylf) distalfrom theT (1 ;13 )1 W abreakpoin t proximallyo nmous echromosom e 1. 5 Inaccurate meiotic chromosome synapsis around the points of partner 45 exchange in the reciprocal translocation T(1;13)70H quadrivalents reduces theviabilit yo fhomozygou stranslocatio n carriers. 6 Non-homologous chromosome synapsis in heteromorphic bivalents and 71 exclusion from meiotic recombination does not impair survival ofprogeny . 7 The capacity ofchromosome s to synapse non-homologouslydurin g meiosis 103 is heritable over successive generations, most likely through an epigenetic mechanism. 8 General discussion 139 References 147 Summary 161 Samenvatting 167 Zusammenfassung 173 Nawoord 179 Curriculum vitae 181 Chapter1 General Introduction Chapter I Introduction In most eukaryotic organisms the sexual reproductive cycle is characterized by an alternation of diploid and haploid generations of cells. The transition from diploid to haploid phase occurs at meiosis. The diploid state is restored by fusion of two haploid cells (gametes) at fertilization. A diploid cell contains two versions of each chromosome, referred to as homologues, one derived from each parent. In the mitotic cell cycle, DNA replication and chromosome condensation are followed by equational segregation of sister chromatids so that the two daughter cells will each inherit the same chromosome complement as the mother cell (fig. 1). In meiosis, a singleroun d of DNAreplicatio n is followed bytw o successive rounds of nuclear division, referred to as meiosis Ian d II (fig. 1).Afte r premeiotic S-phase, during the prophase of meiosis I, chromosomes condense, homologues pair and non-sister chromatids of homologues recombine with each other. Then, at anaphase of meiosis I, homologues move to opposite poles so that the number of chromosomes per nucleus is reduced from the diploid to the haploid number. At meiosis II, sister chromatids segregate as during mitosis. Meiosis thus yields four haploid cells,eac h containing adifferen t and novel assortment ofgenes . Mitosis Meiosis • equational reductional equational Figure 1:Mitosi san dmeiosi s(fro m Kleckner,1996 ) Part I of the introduction focusses on two meiosis specific structures which have been theclassica l objects of cytological research onprophas e Io fmeiosis : synaptonemal complexes (SC) and recombination nodules (RN). Subsequently, recent findings on meiosis in yeast and mammals are described. In Part II, cytological and genetic data on meiosis in mouse heterozygotes for structural chromosome aberrations are described which form the basis of this thesis. Introduction Parti Synaptonemal complexes The SC is aproteinaceous , zipper like structure that holds the homologues in close apposition alongthei r entire length during meioticprophas e (von Wettstein etal, 1984).Followin gDN A replication in premeiotic S-phase, the chromosomes start to condense during the meiotic prophase I at the leptotene stage and each pair of sister chromatids develops a common proteinaceous axis called an axial element (fig. 2). The chromatin itself is organized in loops which are attached to the axial element at their base (Weith and Traut, 1980). In the subsequent zygotene stage, the axial elements become interconnected by numerous thin transverse filaments and a longitudinal structure, called the central element, which develops between the axial elements (Schmekel et al, 1993; Schmekel and Daneholt, 1995). The connecting process and the resulting tripartite structure are called synapsis and SC, respectively (Moses, 1968; von Wettstein et al, 1984). The axial elements within an SC are referred to as lateral elements. During pachytene, all homologues display the SC structure from telomere to telomere and symbolize the bivalents. In early diplotene, the SC starts to disintegrate. In mammals the transverse filaments disappear so that two axial elements per chromosome pair remain. At the end of diplotene and the onset of diakinesis, the axial elements have also disappeared. During the successive zygotene and pachytene substages of meiotic prophase I recombination between non-sister chromatids takes place. During the subsequent diakinesis stage, the bivalents condense further and the scaffolds of the individual sisterchromatid s become discernible. Yet, adhesion between sister chromatids remains intact, aiding in the delineation of chiasmata which are the cytological representations of crossing over between homologous non-sister chromatids. At prometaphase, the nuclear envelope disappears whileth e centromeres becomeattache d to the spindle. Concomitantly, the bivalents orient themselves in preparation of chromosome disjunction. Until disjunction at metaphase I, thehomologue s remain attached to eachothe r byth e chiasmata. Recombination nodules Recombination nodules (RNs) are spherical to ellipsoidal proteinaceous structures approximately 100 nm in diameter that become closely associated with elements of the SC, before and after completion of this structure during prophase I (Carpenter, 1975; von Wettstein et al, 1984; Stack et al, 1993; Stack and Roelofs, 1996). In many eukaryotes, two typeso f RNs canb e distinguished: earlyan d lateones . In plants, numerous early RNs are observed along axial elements at the leptotene stage. At zygotene, early RNs are often observed at sites of convergence between synapsing axial elements of homologous chromosomes and in association with completed SCs (Albini and Jones, 1987; Anderson and Stack, 1988; Zickler et al, 1992). When synapsis is complete at Chapter 1 Leptotene Pachytene chromatid 1 assembling chromatid2 central element of synaptonemaj complex chromatid 3 -M% chromatid 4 I I I Diplotene Interphase Zygotene followed by diakinesis a Leptotene/zygotene Pachytene Prediffuse MetaphaseI diplotene Figure 2: a A schematic representation of the successive stages of meiotic prophase as defined on the basis of morphological changes of the SC: leptotene (proteinaceous axes start to form along homologous chromosomes), zygotene (start of synapsis of homologues), pachytene (synapsis is completed and the SC extends from telomere to telomere), diplotene (SC disassembles) and diakinesis
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