Page last updated: 2024-10-24

homologous chromosome pairing at meiosis

Definition

Target type: biologicalprocess

The meiotic cell cycle process where side by side pairing and physical juxtaposition of homologous chromosomes is created during meiotic prophase. Homologous chromosome pairing begins when the chromosome arms begin to pair from the clustered telomeres and ends when synaptonemal complex or linear element assembly is complete. [GOC:mtg_cell_cycle, PMID:22582262, PMID:23117617, PMID:31811152]

Homologous chromosome pairing, a critical step in meiosis, is a complex process that ensures the proper segregation of chromosomes during cell division. This process starts with the recognition and alignment of homologous chromosomes, which are chromosome pairs with the same genes but potentially different alleles. The initial recognition is facilitated by various factors, including:

1. **Synaptonemal complex (SC) formation:** The SC is a protein structure that forms between homologous chromosomes, acting as a scaffold for their alignment. This structure plays a crucial role in ensuring that homologous chromosomes are properly paired, allowing for genetic exchange through crossing over.

2. **DNA sequence homology:** Homologous chromosomes share high degrees of sequence similarity, enabling them to pair up through a process called "synapsis." This involves the alignment of corresponding DNA sequences on the chromosomes, guided by interactions between specific DNA-binding proteins.

3. **Meiotic recombination:** Recombination, also known as crossing over, is an essential event during meiosis. It involves the exchange of genetic material between homologous chromosomes, increasing genetic diversity. Recombination initiates at specific sites called "recombination initiation sites" (RIS) and occurs at multiple locations along the chromosomes. These exchanges are facilitated by specialized enzymes that break and rejoin DNA strands, creating physical connections between the chromosomes.

4. **Cohesin proteins:** Cohesin proteins are ring-like structures that encircle sister chromatids and keep them together from the time they are replicated until they are separated during anaphase. These proteins also contribute to chromosome pairing, ensuring that homologous chromosomes stay together after they have paired.

After the initial pairing, the homologous chromosomes further align and engage in **synapsis**, a close association that allows for the formation of the SC. This protein structure facilitates the exchange of genetic material through **crossing over** and ensures that homologous chromosomes are properly paired. The SC is essential for the correct alignment of homologous chromosomes, ensuring that they are properly segregated during meiosis.

The process of homologous chromosome pairing is essential for proper chromosome segregation during meiosis. This process ensures that each daughter cell receives one copy of each chromosome, preserving the ploidy of the organism. Errors in homologous chromosome pairing can lead to aneuploidy, a condition where cells have an abnormal number of chromosomes, which can have serious consequences for the organism.
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Proteins (3)

ProteinDefinitionTaxonomy
NAD-dependent protein deacetylase sirtuin-7An NAD-dependent protein deacetylase sirtuin-7 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9NRC8]Homo sapiens (human)
G1/S-specific cyclin-E1A G1/S-specific cyclin-E1 that is encoded in the genome of human. [PRO:DNx]Homo sapiens (human)
G1/S-specific cyclin-E2A G1/S-specific cyclin-E2 that is encoded in the genome of human. [PRO:DNx]Homo sapiens (human)

Compounds (74)

CompoundDefinitionClassesRoles
tyrphostin a23tyrphostin A23: inhibits EGF-stimulated thymidine incorporation as well as EGF-stimulated receptor autophosphorylation & tyrosine phosphorylation & cell proliferation; structure given in first sourcecatechols
bisindolylmaleimide ibisindolylmaleimide I: a bis(indolyl)maleimide
bisindolylmaleimide ivindoles;
maleimides
boheminebohemine : Purine substituted on C-2, C-6 and N-9 with (3-hydroxypropyl)amino, benzylamino and isopropyl groups respectively; a synthetic, cell-permeable, cyclin-dependent kinase (CDK) inhibitor that is structurally similar to olomoucine and roscovitine.purinesEC 2.7.11.22 (cyclin-dependent kinase) inhibitor
n(6),n(6)-dimethyladenineN(6),N(6)-dimethyladenine : A tertiary amine that is adenine substituted at N-6 by geminal methyl groups.tertiary amine
gw8510GW8510: 3' substituted indolone as a scaffold for the development of neuroprotective drug; structure in first source
indirubin-3'-monoximeindirubin-3'-monoxime : A member of the class of biindoles that is indirubin in which the keto group at position 3' has undergone condensation with hydroxylamine to form the corresponding oxime.

indirubin-3'-monoxime: has antiangiogenic activity
staurosporine aglyconestaurosporine aglycone: metabolite from culture broth of Nocardiopsis sp.; a neurotrophin antag; inhibits BDNF TrkB receptor
nu6102NU6102: structure in first source
olomoucineolomoucine : A 9H-purine that is substituted by a (2-hydroxyethyl)nitrilo, benzylnitrilo and a methyl group at positions 2,6 and 9, respectively. It is a cyclin-dependent kinase inhibitor.

olomoucine: inhibits protein P34CDC2
2,6-diaminopurines;
ethanolamines
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
imatinibaromatic amine;
benzamides;
N-methylpiperazine;
pyridines;
pyrimidines
antineoplastic agent;
apoptosis inducer;
tyrosine kinase inhibitor
indirubin
indigohydroxyindoles
staurosporineindolocarbazole alkaloid;
organic heterooctacyclic compound
apoptosis inducer;
bacterial metabolite;
EC 2.7.11.13 (protein kinase C) inhibitor;
geroprotector
fascaplysinefascaplysine: from tropic sea sponges
LSM-4272beta-carbolines
dehydroabietic aciddehydroabietate : A monocarboxylic acid anion that is the conjugate base of dehydroabietic acid, obtained by deprotonation of the carboxy group.

dehydroabietic acid : An abietane diterpenoid that is abieta-8,11,13-triene substituted at position 18 by a carboxy group.

dehydroabietic acid: major aquatic toxicant in effluent of pulp and paper mills
abietane diterpenoid;
carbotricyclic compound;
monocarboxylic acid
allergen;
metabolite
birb 796aromatic ether;
morpholines;
naphthalenes;
pyrazoles;
ureas
EC 2.7.11.24 (mitogen-activated protein kinase) inhibitor;
immunomodulator
cyc 202seliciclib : 2,6-Diaminopurine carrying benzylamino, (2R)-1-hydroxybutan-2-yl and isopropyl substituents at C-6, C-2-N and N-9 respectively. It is an experimental drug candidate in the family of pharmacological cyclin-dependent kinase (CDK) inhibitors.2,6-diaminopurinesantiviral drug;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
lapatinibfurans;
organochlorine compound;
organofluorine compound;
quinazolines
antineoplastic agent;
tyrosine kinase inhibitor
2H-pyrazolo[4,3-b]quinoxalin-3-aminequinoxaline derivative
7-n-butyl-6-(4'-hydroxyphenyl)-5h-pyrrolo(2,3b)pyrazine
6-bromoindirubin-3'-oxime6-bromoindirubin-3'-oxime : A member of the class of biindoles that is indirubin substituted at position 6 by a bromo group and in which the keto group at position 3' has undergone condensation with hydroxylamine to form the corresponding oxime.

6-bromoindirubin-3'-oxime: structure in first source
purvalanol bpurvalanol B: protein kinase inhibitor; structure in first sourcepurvalanolprotein kinase inhibitor
repsoxRepSox: inhibits TGF-beta signaling; structure in first source appears to be incorrectpyrazolopyridine
purvalanol a6-((3-chloro)anilino)-2-(isopropyl-2-hydroxyethylamino)-9-isopropylpurine: purvalanol A is the (1R)-isomer;purvalanol
2-methyl-5-(4-methylanilino)-1,3-benzothiazole-4,7-dioneaminotoluene
cgp 60474substituted aniline
cgp 74514a
1,4-dimethoxy-10H-acridine-9-thioneacridines
bms 387032N-(5-(((5-(1,1-dimethylethyl)-2-oxazolyl)methyl)thio)-2-thiazolyl)-4-piperidinecarboxamide: a CDK2 inhibitor with antineoplastic activity; structure in first source

N-(5-{[(5-tert-butyl-1,3-oxazol-2-yl)methyl]sulfanyl}-1,3-thiazol-2-yl)piperidine-4-carboxamide : A secondary carboxamide resulting from the formal condensation of the carboxy group of piperidine-4-carboxylic acid with the amino group of 5-{[(5-tert-butyl-1,3-oxazol-2-yl)methyl]sulfanyl}-1,3-thiazol-2-amine. It is an ATP-competitive inhibitor of CDK2, CDK7 and CDK9 kinases and exhibits anti-cancer properties.
1,3-oxazoles;
1,3-thiazoles;
organic sulfide;
piperidinecarboxamide;
secondary carboxamide
angiogenesis inhibitor;
antineoplastic agent;
apoptosis inducer;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
sf 2370K-252a : A organic heterooctacyclic compound that is a potent inhibitor of protein kinase C and is isolated from Nocardiopsis sp K-252a

SF 2370: indolocarbazole isolated from Actinomadura sp. SF-2370; structure given in first source
bridged compound;
gamma-lactam;
methyl ester;
organic heterooctacyclic compound
antimicrobial agent;
bacterial metabolite;
EC 2.7.11.13 (protein kinase C) inhibitor;
tropomyosin-related kinase B receptor antagonist
sb 218078indolocarbazole
7-butyl-6-(4-methoxyphenyl)-5H-pyrrolo[2,3-b]pyrazinepyrroles
alvocidibalvocidib : A synthetic dihydroxyflavone that is 5,7-dihydroxyflavone which is substituted by a 3-hydroxy-1-methylpiperidin-4-yl group at position 8 and by a chlorine at the 2' position (the (-)-3S,4R stereoisomer). A cyclin-dependent kinase 9 (CDK9) inhibitor, it has been studied for the treatment of acute myeloid leukaemia, arthritis and atherosclerotic plaque formation.

alvocidib: structure given in first source
dihydroxyflavone;
hydroxypiperidine;
monochlorobenzenes;
tertiary amino compound
antineoplastic agent;
antirheumatic drug;
apoptosis inducer;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
aftin-4aftin-4: increases production of amyloid-beta protein (1-42)
su 9516
arcyriaflavin aarcyriaflavin A: from marine ascidian, Eudistoma sp.; structure given in first sourceindolocarbazole
pd 0183812PD 0183812: inhibits CDK4 and CDK6; structure in first source
palbociclibaminopyridine;
aromatic ketone;
cyclopentanes;
piperidines;
pyridopyrimidine;
secondary amino compound;
tertiary amino compound
antineoplastic agent;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
olomoucine iiolomoucine II: structure in first source
cyc 1164-methyl-5-(2-(4-morpholinophenylamino)pyrimidin-4-yl)thiazol-2-amine: an aurora kinase inhibitor; structure in first source
2-[[6-[(phenylmethyl)amino]-9-propan-2-yl-2-purinyl]amino]ethanolthiopurine
cvt 313CVT 313: a potent inhibitor of CDK2 that prevents neointimal proliferation; structure given in first source
panobinostatpanobinostat : A hydroxamic acid obtained by formal condensation of the carboxy group of (2E)-3-[4-({[2-(2-methylindol-3-yl)ethyl]amino}methyl)phenyl]prop-2-enoic acid with the amino group of hydroxylamine. A histone deacetylase inhibitor used (as its lactate salt) in combination with bortezomib and dexamethasone for the treatment of multiple myeloma.

Panobinostat: An indole and hydroxamic acid derivative that acts as a HISTONE DEACETYLASE inhibitor. It is used as an antineoplastic agent in combination with BORTEZOMIB and DEXAMETHASONE for the treatment of MULTIPLE MYELOMA.
cinnamamides;
hydroxamic acid;
methylindole;
secondary amino compound
angiogenesis modulating agent;
antineoplastic agent;
EC 3.5.1.98 (histone deacetylase) inhibitor
((3z)-n-(3-chlorophenyl)-3-((3,5-dimethyl-4-((4-methylpiperazin-1-yl)carbonyl)-1h-pyrrol-2-yl)methylene)-n-methyl-2-oxo-2,3-dihydro-1h-indole-5-sulfonamide)sulfonamide
azd2858aromatic amine;
N-methylpiperazine;
pyrazines;
pyridines;
secondary carboxamide;
sulfonamide
antineoplastic agent;
bone density conservation agent;
EC 2.7.11.26 (tau-protein kinase) inhibitor;
Wnt signalling activator
nu 61404-(6-cyclohexylmethoxy-9H-purin-2-ylamino)-N,N-diethylbenzamide: a cyclin-dependent kinase inhibitor; structure in first source
rgb 286638
at 75194-(2,6-dichlorobenzamido)-N-(piperidin-4-yl)-pyrazole-3-carboxamide : A member of the class of pryrazoles that is 4-amino-1H-pyrazole-3-carboxylic acid in which the primary amino group has been acylated by a 2,6-dichlorobenzoyl group and in which the carboxylic acid has been converted into a carboxamide by formal condensation with the primary amino group of 4-aminopiperidine.dichlorobenzene;
piperidines;
pyrazoles;
secondary carboxamide
antineoplastic agent;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
quisinostatindoles
pha 848125N,1,4,4-tetramethyl-8-((4-(4-methylpiperazin-1-yl)phenyl)amino)-4,5-dihydro-1H-pyrazolo(4,3-h)quinazoline-3-carboxamide: a cyclin dependent kinase inhibitor
14-methyl-20-oxa-5,7,14,26-tetraazatetracyclo(19.3.1.1(2,6).1(8,12))heptacosa-1(25),2(26),3,5,8(27),9,11,16,21,23-decaene14-methyl-20-oxa-5,7,14,26-tetraazatetracyclo(19.3.1.1(2,6).1(8,12))heptacosa-1(25),2(26),3,5,8(27),9,11,16,21,23-decaene: has antineoplastic activity; also inhibits Fms-like tyrosine kinase-3; structure in first source
azd5438sulfonamide
p276-00P276-00: antineoplastic, cyclin-dependent kinase inhibitor; structure in first source
cx 4945
bms 754807BMS 754807: an IGR-1R kinase inhibitor; structure in first sourcepyrazoles;
pyridines;
pyrrolidines;
pyrrolotriazine
antineoplastic agent;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor
pci 32765ibrutinib : A member of the class of acrylamides that is (3R)-3-[4-amino-3-(4-phenoxyphenyl)pyrazolo[3,4-d]pyrimidin-1-yl]piperidine in which the piperidine nitrogen is replaced by an acryloyl group. A selective and covalent inhibitor of the enzyme Bruton's tyrosine kinase, it is used for treatment of B-cell malignancies.

ibrutinib: a Btk protein inhibitor
acrylamides;
aromatic amine;
aromatic ether;
N-acylpiperidine;
pyrazolopyrimidine;
tertiary carboxamide
antineoplastic agent;
EC 2.7.10.2 (non-specific protein-tyrosine kinase) inhibitor
cink4CINK4: cyclin-dependent kinase 4 inhibitor; may have tumor suppression activity; structure in first sourceindoles
bs 194
(R)-DRF053(R)-DRF053 : A member of the class of 2,6-diaminopurines that is 2,6-diamiopurine which is substituted by an isopropyl group at position 9 and in which the amino groups at positions 2 and 6 are substituted by a 1-hydroxybutan-2-yl and 3-(pyridin-2-yl)phenyl groups, respectively (the R enantiomer). A cyclin dependent kinase inhibitor, widely used as its hydrochloride hydrate.2,6-diaminopurines;
phenylpyridine;
primary alcohol;
secondary amino compound
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
ribociclibribociclib: inhibits both CDK4 and CDK6
bay 1000394roniciclib: an antineoplastic agent that inhibits cyclin-dependent kinases; structure in first source
pha 793887piperidinecarboxamide
abemaciclib
dinaciclibpyrazolopyrimidine
nms p937NMS P937: a polo-like kinase 1 inhibitor; structure in first source
gilteritinibgilteritinib : A member of the class of pyrazines that is pyrazine-2-carboxamide which is substituted by {3-methoxy-4-[4-(4-methylpiperazin-1-yl)piperidin-1-yl]phenyl}nitrilo, (oxan-4-yl)nitrilo and ethyl groups at positions 3,5 and 6, respectively. It is a potent inhibitor of FLT3 and AXL tyrosine kinase receptors (IC50 = 0.29 nM and 0.73 nM, respectively). Approved by the FDA for the treatment of acute myeloid leukemia in patients who have a FLT3 gene mutation.

gilteritinib: an FLT3/AXL protein tyrosine kinase inhibitor
aromatic amine;
monomethoxybenzene;
N-methylpiperazine;
oxanes;
piperidines;
primary carboxamide;
pyrazines;
secondary amino compound
antineoplastic agent;
apoptosis inducer;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor
bs-181BS-181: a CDK7 inhibitor with antineoplastic activitypyrazolopyrimidine
butyrolactone ibutyrolactone I: selective inhibitor of cdk2 & cdc2 kinase; structure given in first sourcebutenolide
on123300ON123300: a protein kinase inhibitor; structure in first source
can 508CAN 508: has antiangiogenic activity; structure in first source

CAN-508 : A member of the class of pyrazoles that is 1H-pyrazole substituted by amino, (4-hydroxyphenyl)diazenyl, and amino groups at positions 3, 4 and 5, respectively. It is a CDK9 inhibitor (IC50 = 0.35 muM) with 38-fold selectivity for CDK9/cyclin T over other CDK/cyclin complexes.
aromatic amine;
monoazo compound;
phenols;
pyrazoles
angiogenesis inhibitor;
antineoplastic agent;
apoptosis inducer;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
ro 3306RO 3306: structure in first source
hymenialdisine