TY - JOUR
T1 - B chromosomes in the grasshopper Eyprepocnemis plorans are present in all body parts analyzed and show extensive variation for rDNA copy number
AU - Ruiz-Estévez, Mercedes
AU - Cabrero, Josefa
AU - Camacho, Juan Pedro M.
AU - López-León, María Dolores
PY - 2014/1/1
Y1 - 2014/1/1
N2 - B chromosomes in the grasshopper Eyprepocnemis plorans are considered to be mitotically stable, because all meiotic (primary spermatocytes and oocytes) or mitotic (embryos, ovarioles, and gastric caecum) cells analyzed within the same individual show the same B chromosome number. Nothing is known, however, about body parts with somatic tissues with no mitotic activity in adult individuals, constituting the immense majority of their body. Therefore, we investigated whether B chromosomes are present in 8 non-mitotically active somatic body parts from both sexes in addition to ovarioles and testes by PCR analysis of 2 B-specific molecular markers. We also elucidated the number of B chromosomes that an individual carried through quantifying the Blocated rDNA copy number by qPCR. Our results indicated the amplification of both B-specific markers in all analyzed body parts. However, we found high variation between males for the estimated number of rDNA units in the B chromosomes. These results demonstrate the presence of B chromosomes in all body parts from the same individual and suggest a high variation in the rDNA content of the B chro-mosomes carried by different individuals from the same population, presumably due to unequal crossovers during meiosis.
AB - B chromosomes in the grasshopper Eyprepocnemis plorans are considered to be mitotically stable, because all meiotic (primary spermatocytes and oocytes) or mitotic (embryos, ovarioles, and gastric caecum) cells analyzed within the same individual show the same B chromosome number. Nothing is known, however, about body parts with somatic tissues with no mitotic activity in adult individuals, constituting the immense majority of their body. Therefore, we investigated whether B chromosomes are present in 8 non-mitotically active somatic body parts from both sexes in addition to ovarioles and testes by PCR analysis of 2 B-specific molecular markers. We also elucidated the number of B chromosomes that an individual carried through quantifying the Blocated rDNA copy number by qPCR. Our results indicated the amplification of both B-specific markers in all analyzed body parts. However, we found high variation between males for the estimated number of rDNA units in the B chromosomes. These results demonstrate the presence of B chromosomes in all body parts from the same individual and suggest a high variation in the rDNA content of the B chro-mosomes carried by different individuals from the same population, presumably due to unequal crossovers during meiosis.
KW - B chromosomes
KW - FISH
KW - Mitotic stability
KW - qPCR
KW - rDNA
UR - http://www.scopus.com/inward/record.url?scp=84908616404&partnerID=8YFLogxK
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U2 - 10.1159/000365797
DO - 10.1159/000365797
M3 - Article
C2 - 25138924
AN - SCOPUS:84908616404
VL - 143
SP - 268
EP - 274
JO - Cytogenetic and Genome Research
JF - Cytogenetic and Genome Research
SN - 1424-8581
IS - 4
ER -