PMID- 35064347
OWN - NLM
STAT- MEDLINE
DCOM- 20220509
LR  - 20220509
IS  - 1573-6849 (Electronic)
IS  - 0967-3849 (Linking)
VI  - 30
IP  - 1
DP  - 2022 Mar
TI  - The Arabidopsis HOP2 gene has a role in preventing illegitimate connections 
      between nonhomologous chromosome regions.
PG  - 59-75
LID - 10.1007/s10577-021-09681-2 [doi]
AB  - Meiotic homologous chromosomes synapse and undergo crossing over (CO). In many 
      eukaryotes, both synapsis and crossing over require the induction of double 
      stranded breaks (DSBs) and subsequent repair via homologous recombination. In 
      these organisms, two key proteins are recombinases RAD51 and DMC1. 
      Recombinase-modulators HOP2 and MND1 assist RAD51 and DMC1 and also are required 
      for synapsis and CO. We have investigated the hop2-1 phenotype in Arabidopsis 
      during the segregation stages of both meiosis and mitosis. Despite a general lack 
      of synapsis during prophase I, we observed extensive, stable interconnections 
      between nonhomologous chromosomes in diploid hop2-1 nuclei in first and second 
      meiotic divisions. Using gammaH2Ax as a marker of unrepaired DSBs, we detected gammaH2AX 
      foci from leptotene through early pachytene but saw no foci from mid-pachytene 
      onward. We conclude that the bridges seen from metaphase I onward are due to 
      mis-repaired DSBs, not unrepaired ones. Examining haploids, we found that wild 
      type haploids produce only univalents, but hop2-1 haploids like hop2-1 diploids 
      have illegitimate connections stable enough to produce bridged chromosomes during 
      segregation. Our results suggest that HOP2 has a significant active role in 
      preventing repairs that use nonhomologous chromosomes during meiosis. We also 
      found evidence that HOP2 plays a role in preventing illegitimate repair of 
      radiation-induced DSBs in rapidly dividing petal cells. We conclude that HOP2 in 
      Arabidopsis plays both a positive role in promoting synapsis and a separable role 
      in preventing DSB repair using nonhomologous chromosomes. SIGNIFICANCE STATEMENT 
      : The fidelity of homologous recombination (HR) during meiosis is essential to 
      the production of viable gametes and for maintaining genome integrity in 
      vegetative cells. HOP2 is an important protein for accurate meiotic HR in plants. 
      We have found evidence of high levels of illegitimate repairs between 
      nonhomologous chromosomes during meiosis and in irradiated petal cells in hop2-1 
      mutants, suggesting a role for HOP2 beyond its established role in synapsis and 
      crossing over.
CI  - (c) 2021. The Author(s), under exclusive licence to Springer Nature B.V.
FAU - Farahani-Tafreshi, Yisell
AU  - Farahani-Tafreshi Y
AD  - University of Toronto Scarborough, Toronto, ON, Canada.
FAU - Wei, Chun
AU  - Wei C
AD  - University of Toronto Scarborough, Toronto, ON, Canada.
FAU - Gan, Peilu
AU  - Gan P
AD  - University of Toronto Scarborough, Toronto, ON, Canada.
FAU - Daradur, Jenya
AU  - Daradur J
AD  - University of Toronto Scarborough, Toronto, ON, Canada.
FAU - Riggs, C Daniel
AU  - Riggs CD
AD  - University of Toronto Scarborough, Toronto, ON, Canada.
FAU - Hasenkampf, Clare A
AU  - Hasenkampf CA
AUID- ORCID: 0000-0002-8030-5781
AD  - University of Toronto Scarborough, Toronto, ON, Canada. c.hasenkampf@utoronto.ca.
LA  - eng
GR  - RGPGP-2015-00071 (CAH &CDR)/Natural Sciences and Engineering Research Council 
      of Canada/
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20220122
PL  - Netherlands
TA  - Chromosome Res
JT  - Chromosome research : an international journal on the molecular, supramolecular 
      and evolutionary aspects of chromosome biology
JID - 9313452
RN  - 0 (Cell Cycle Proteins)
RN  - 0 (DNA-Binding Proteins)
RN  - EC 2.7.7.- (Rad51 Recombinase)
SB  - IM
MH  - *Arabidopsis/genetics
MH  - Cell Cycle Proteins/metabolism
MH  - Chromosome Pairing
MH  - Chromosomes/metabolism
MH  - DNA-Binding Proteins/metabolism
MH  - Meiosis
MH  - Rad51 Recombinase/genetics
OTO - NOTNLM
OT  - Chromosome movement
OT  - DMC1
OT  - HOP2
OT  - Haploids
OT  - Homologous Recombination
OT  - MND1
OT  - NonHomologous End Joining
OT  - gammaH2AX
EDAT- 2022/01/23 06:00
MHDA- 2022/05/10 06:00
CRDT- 2022/01/22 05:45
PHST- 2021/08/17 00:00 [received]
PHST- 2021/12/08 00:00 [accepted]
PHST- 2021/12/04 00:00 [revised]
PHST- 2022/01/23 06:00 [pubmed]
PHST- 2022/05/10 06:00 [medline]
PHST- 2022/01/22 05:45 [entrez]
AID - 10.1007/s10577-021-09681-2 [pii]
AID - 10.1007/s10577-021-09681-2 [doi]
PST - ppublish
SO  - Chromosome Res. 2022 Mar;30(1):59-75. doi: 10.1007/s10577-021-09681-2. Epub 2022 
      Jan 22.