Abstract
In the tetraploid somatic hybrid between the diploid Lycopersicon species L. esculentum (tomato) and L. peruvianum, synaptonemal complexes formed quadrivalents in 73 of the 120 sets of four chromosomes (60.8%) in 10 cells studied in detail at pachytene. Of these, 43 had one pairing partner exchange, 22 had two, and 8 had three, very close to a Poisson distribution. The points of pairing partner exchange were concentrated at the middle of the two arms. The frequency per arm corresponded with physical arm length. There was a sharp drop around the centromere, and pericentric heterochromatin had a slightly lower probability of being involved in pairing partner exchange than euchromatin. The chromosomes align before pairing and there are several points of pairing initiation, with concentrations at or near the ends and the centromere. From zygotene to late pachytene the quadrivalent frequency decreased considerably. At late pachytene it was lower than expected with the observed high frequency of pairing partner exchange. Pairing affinity between species was only slightly lower than affinity within species, in spite of considerable genetic differentiation. The frequency of recombination nodules increased from early to late zygotene and then decreased strongly to full pachytene. There is a highly significant negative correlation between percent pairing and SC length. At metaphase I the frequency of quadrivalents was 0.444, and branched quadrivalents were rare, probably caused by interference and restriction of chiasma formation to distal euchromatin. Metaphase I quadrivalent frequency is a relatively good indication of pairing affinity in this material.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 19
Claim · model-written summary
Quadrivalents formed in 73 of 120 chromosome sets (60.8%) in 10 pachytene cells.
- Taxon
- L. esculentum (tomato) and L. peruvianum
Solanum lycopersicumSolanum peruvianume0 - Organ / stage
- pachytenee0
- Outcome
- synaptonemal complexes formed quadrivalentse0
- Value
- 60.8%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“L. esculentum (tomato) and L. peruvianum, synaptonemal complexes formed quadrivalents in 73 of the 120 sets of four chromosomes (60.8%) in 10 cells studied in detail at pachytene”
Claim · model-written summary
Among quadrivalents, 43 had one pairing partner exchange.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- one pairing partner exchangee0
- Value
- 43e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Of these, 43 had one pairing partner exchange, 22 had two, and 8 had three, very close to a Poisson distribution”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Among quadrivalents, 22 had two pairing partner exchanges.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- pairing partner exchangee0
- Value
- 22e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Of these, 43 had one pairing partner exchange, 22 had two, and 8 had three, very close to a Poisson distribution”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Among quadrivalents, eight had three pairing partner exchanges.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- pairing partner exchangee0
- Value
- 8e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Of these, 43 had one pairing partner exchange, 22 had two, and 8 had three, very close to a Poisson distribution”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Pairing partner exchanges were concentrated in the middle of chromosome arms.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- points of pairing partner exchange were concentrated at the middle of the two armse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The points of pairing partner exchange were concentrated at the middle of the two arms”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Exchange frequency per arm corresponded with physical arm length.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Organ / stage
- arme0
- Outcome
- frequency per arme0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The frequency per arm corresponded with physical arm length”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Pairing partner exchange dropped sharply around the centromere.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- sharp drop around the centromeree0
- Direction
- drope0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was a sharp drop around the centromere”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Pericentric heterochromatin had slightly less exchange than euchromatin.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- probability of being involved in pairing partner exchangee0
- Direction
- lowere0
- Comparator
- euchromatine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“pericentric heterochromatin had a slightly lower probability of being involved in pairing partner exchange than euchromatin”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Chromosomes aligned before pairing, with several initiation points concentrated near ends and centromeres.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- chromosomes align before pairing and there are several points of pairing initiatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The chromosomes align before pairing and there are several points of pairing initiation, with concentrations at or near the ends and the centromere”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Quadrivalent frequency declined considerably from zygotene to late pachytene.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- quadrivalent frequencye0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“From zygotene to late pachytene the quadrivalent frequency decreased considerably”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Late pachytene quadrivalent frequency was lower than expected from exchange frequency.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- frequency of pairing partner exchangee0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At late pachytene it was lower than expected with the observed high frequency of pairing partner exchange”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Between-species pairing affinity was only slightly lower than within-species affinity.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- Pairing affinity between speciese0
- Direction
- lowere0
- Comparator
- affinity within speciese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pairing affinity between species was only slightly lower than affinity within species”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Recombination nodule frequency rose from early to late zygotene.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- frequency of recombination nodulese0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The frequency of recombination nodules increased from early to late zygotene and then decreased strongly to full pachytene”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Recombination nodule frequency fell strongly by full pachytene.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- frequency of recombination nodulese0
- Direction
- decreased stronglye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The frequency of recombination nodules increased from early to late zygotene and then decreased strongly to full pachytene”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Percent pairing and synaptonemal complex length were strongly negatively correlated.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Organ / stage
- SCe0
- Outcome
- percent pairinge0
- Direction
- negative correlatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There is a highly significant negative correlation between percent pairing and SC length”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Metaphase I quadrivalent frequency was 0.444.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- frequency of quadrivalentse0
- Value
- 0.444e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At metaphase I the frequency of quadrivalents was 0.444”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Branched quadrivalents were rare at metaphase I.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- branched quadrivalents were raree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“branched quadrivalents were rare”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
The authors suggest interference and distal chiasma restriction caused rare branched quadrivalents.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- branched quadrivalents were raree0
- Qualifier
- interference and restriction of chiasma formation to distal euchromatine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“branched quadrivalents were rare, probably caused by interference and restriction of chiasma formation to distal euchromatin”
t0“Lycopersicon esculentum × L. peruvianum hybrid”
Claim · model-written summary
Metaphase I quadrivalent frequency relatively well indicates pairing affinity.
- Taxon
- Lycopersicon esculentum × L. peruvianumSolanum lycopersicumt0
- Outcome
- indication of pairing affinitye0
- Comparator
- pairing affinitye0
Not reportedValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Metaphase I quadrivalent frequency is a relatively good indication of pairing affinity in this material”
t0“Lycopersicon esculentum × L. peruvianum hybrid”