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)
| Protein | Definition | Taxonomy |
|---|---|---|
| NAD-dependent protein deacetylase sirtuin-7 | An 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-E1 | A G1/S-specific cyclin-E1 that is encoded in the genome of human. [PRO:DNx] | Homo sapiens (human) |
| G1/S-specific cyclin-E2 | A G1/S-specific cyclin-E2 that is encoded in the genome of human. [PRO:DNx] | Homo sapiens (human) |
Compounds (74)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| tyrphostin a23 | tyrphostin A23: inhibits EGF-stimulated thymidine incorporation as well as EGF-stimulated receptor autophosphorylation & tyrosine phosphorylation & cell proliferation; structure given in first source | catechols | |
| bisindolylmaleimide i | bisindolylmaleimide I: a bis(indolyl)maleimide | ||
| bisindolylmaleimide iv | indoles; maleimides | ||
| bohemine | bohemine : 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. | purines | EC 2.7.11.22 (cyclin-dependent kinase) inhibitor |
| n(6),n(6)-dimethyladenine | N(6),N(6)-dimethyladenine : A tertiary amine that is adenine substituted at N-6 by geminal methyl groups. | tertiary amine | |
| gw8510 | GW8510: 3' substituted indolone as a scaffold for the development of neuroprotective drug; structure in first source | ||
| indirubin-3'-monoxime | indirubin-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 aglycone | staurosporine aglycone: metabolite from culture broth of Nocardiopsis sp.; a neurotrophin antag; inhibits BDNF TrkB receptor | ||
| nu6102 | NU6102: structure in first source | ||
| olomoucine | olomoucine : 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 |
| imatinib | aromatic amine; benzamides; N-methylpiperazine; pyridines; pyrimidines | antineoplastic agent; apoptosis inducer; tyrosine kinase inhibitor | |
| indirubin | |||
| indigo | hydroxyindoles | ||
| staurosporine | indolocarbazole alkaloid; organic heterooctacyclic compound | apoptosis inducer; bacterial metabolite; EC 2.7.11.13 (protein kinase C) inhibitor; geroprotector | |
| fascaplysine | fascaplysine: from tropic sea sponges | ||
| LSM-4272 | beta-carbolines | ||
| dehydroabietic acid | dehydroabietate : 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 796 | aromatic ether; morpholines; naphthalenes; pyrazoles; ureas | EC 2.7.11.24 (mitogen-activated protein kinase) inhibitor; immunomodulator | |
| cyc 202 | seliciclib : 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-diaminopurines | antiviral drug; EC 2.7.11.22 (cyclin-dependent kinase) inhibitor |
| lapatinib | furans; organochlorine compound; organofluorine compound; quinazolines | antineoplastic agent; tyrosine kinase inhibitor | |
| 2H-pyrazolo[4,3-b]quinoxalin-3-amine | quinoxaline derivative | ||
| 7-n-butyl-6-(4'-hydroxyphenyl)-5h-pyrrolo(2,3b)pyrazine | |||
| 6-bromoindirubin-3'-oxime | 6-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 b | purvalanol B: protein kinase inhibitor; structure in first source | purvalanol | protein kinase inhibitor |
| repsox | RepSox: inhibits TGF-beta signaling; structure in first source appears to be incorrect | pyrazolopyridine | |
| purvalanol a | 6-((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-dione | aminotoluene | ||
| cgp 60474 | substituted aniline | ||
| cgp 74514a | |||
| 1,4-dimethoxy-10H-acridine-9-thione | acridines | ||
| bms 387032 | N-(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 2370 | K-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 218078 | indolocarbazole | ||
| 7-butyl-6-(4-methoxyphenyl)-5H-pyrrolo[2,3-b]pyrazine | pyrroles | ||
| alvocidib | alvocidib : 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-4 | aftin-4: increases production of amyloid-beta protein (1-42) | ||
| su 9516 | |||
| arcyriaflavin a | arcyriaflavin A: from marine ascidian, Eudistoma sp.; structure given in first source | indolocarbazole | |
| pd 0183812 | PD 0183812: inhibits CDK4 and CDK6; structure in first source | ||
| palbociclib | aminopyridine; aromatic ketone; cyclopentanes; piperidines; pyridopyrimidine; secondary amino compound; tertiary amino compound | antineoplastic agent; EC 2.7.11.22 (cyclin-dependent kinase) inhibitor | |
| olomoucine ii | olomoucine II: structure in first source | ||
| cyc 116 | 4-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]ethanol | thiopurine | ||
| cvt 313 | CVT 313: a potent inhibitor of CDK2 that prevents neointimal proliferation; structure given in first source | ||
| panobinostat | panobinostat : 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 | ||
| azd2858 | aromatic 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 6140 | 4-(6-cyclohexylmethoxy-9H-purin-2-ylamino)-N,N-diethylbenzamide: a cyclin-dependent kinase inhibitor; structure in first source | ||
| rgb 286638 | |||
| at 7519 | 4-(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 |
| quisinostat | indoles | ||
| pha 848125 | N,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-decaene | 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-decaene: has antineoplastic activity; also inhibits Fms-like tyrosine kinase-3; structure in first source | ||
| azd5438 | sulfonamide | ||
| p276-00 | P276-00: antineoplastic, cyclin-dependent kinase inhibitor; structure in first source | ||
| cx 4945 | |||
| bms 754807 | BMS 754807: an IGR-1R kinase inhibitor; structure in first source | pyrazoles; pyridines; pyrrolidines; pyrrolotriazine | antineoplastic agent; EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor |
| pci 32765 | ibrutinib : 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 |
| cink4 | CINK4: cyclin-dependent kinase 4 inhibitor; may have tumor suppression activity; structure in first source | indoles | |
| 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 |
| ribociclib | ribociclib: inhibits both CDK4 and CDK6 | ||
| bay 1000394 | roniciclib: an antineoplastic agent that inhibits cyclin-dependent kinases; structure in first source | ||
| pha 793887 | piperidinecarboxamide | ||
| abemaciclib | |||
| dinaciclib | pyrazolopyrimidine | ||
| nms p937 | NMS P937: a polo-like kinase 1 inhibitor; structure in first source | ||
| gilteritinib | gilteritinib : 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-181 | BS-181: a CDK7 inhibitor with antineoplastic activity | pyrazolopyrimidine | |
| butyrolactone i | butyrolactone I: selective inhibitor of cdk2 & cdc2 kinase; structure given in first source | butenolide | |
| on123300 | ON123300: a protein kinase inhibitor; structure in first source | ||
| can 508 | CAN 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 3306 | RO 3306: structure in first source | ||
| hymenialdisine |