First constitutive heterochromatin characterization and Karyotype of white stork Ciconia ciconia (Aves: Ciconiidae) / Primeira caracterização constitutiva de heterocromatina e cariótipo de cegonhabranca Ciconia ciconia (Aves: Ciconiidae)

The karyotype and constitutive heterochromatin pattern of the white stork Ciconia ciconia samples obtained from Manzala lake, Dimiaat, Egypt was described. Somatic cells of Ciconia ciconia samples have diploid number 2n= 68 chromosomes. Out of 68 chromosomes, 11 pairs including sex chromosomes were macrochromosomes and the remaining pairs were microchromosomes. Of the 11 macrochromosome pairs, no.1, 2, 4 and 5 were submetacentric and pairs no. 6, 7 and 8 were described as metacentric. In addition, the autosome pair no.3 was subtelocentric, while autosome pair no.9 was acrocentric. Also, the sex chromosome Z represents the fourth one in size and it was classified as submetacentric while, W chromosome appeared as medium size and was acrocentric. Furthermore, C-banding pattern (constitutive heterochromatin) revealed variation in their sizes and occurrence between macrochromosomes. Pairs no. 7 and 8 of autosomes exhibited unusual distribution of heterochromatin, where they appeared as entirely heterochromatic. This may be related to the origin of sex chromosomes Z and W. However, there is no sufficient evidence illustrate the appearance of entirely heterochromatic autosomes. Therefore, there is no available cytogenetic literature that describes the C-banding and karyotype of Ciconia Ciconia, so the results herein are important and may assist in cytogenetic study and evolutionary pattern of Ciconiiformes.

O cariótipo e o padrão constitutivo de heterocromatina das amostras de cegonha-branca Ciconia ciconia obtidas no lago Manzala, Dimiaat, Egito, foram descritos. As células somáticas de amostras de Ciconia ciconia possuem número diploide 2n = 68 cromossomos. Dos 68 cromossomos, 11 pares incluindo cromossomos sexuais eram macrocromossomos e os pares restantes eram microcromossomos. Dos 11 pares de macrocromossomos, os nos 1, 2, 4 e 5 eram submetacêntricos, e os pares nos 6, 7 e 8 foram descritos como metacêntricos. Além disso, o par de autossomos no 3 era subtelocêntrico, enquanto o par de autossomos no 9 era acrocêntrico. Além disso, o cromossomo sexual Z representa o quarto em tamanho e foi classificado como submetacêntrico, enquanto o cromossomo W apareceu como de tamanho médio e acrocêntrico. Além disso, o padrão de bandamento C (heterocromatina constitutiva) revelou variação em seus tamanhos e ocorrência entre macrocromossomos. Pares nºs 7 e 8 dos autossomos exibiram distribuição incomum de heterocromatina, onde apareceram como totalmente heterocromáticos. Isso pode estar relacionado à origem dos cromossomos sexuais Z e W. No entanto, não há evidências suficientes para ilustrar o aparecimento de autossomos totalmente heterocromáticos. Portanto, não há literatura citogenética disponível que descreva o bandamento C e o cariótipo de Ciconia ciconia, portanto os resultados aqui apresentados são importantes e podem auxiliar no estudo citogenético e no padrão evolutivo de Ciconiiformes.

First constitutive heterochromatin characterization and Karyotype of white stork Ciconia ciconia (Aves: Ciconiidae)

Abstract The karyotype and constitutive heterochromatin pattern of the white stork Ciconia ciconia samples obtained from Manzala lake, Dimiaat, Egypt was described. Somatic cells of Ciconia ciconia samples have diploid number 2n= 68 chromosomes. Out of 68 chromosomes, 11 pairs including sex chromosomes were macrochromosomes and the remaining pairs were microchromosomes. Of the 11 macrochromosome pairs, no.1, 2, 4 and 5 were submetacentric and pairs no. 6, 7 and 8 were described as metacentric. In addition, the autosome pair no.3 was subtelocentric, while autosome pair no.9 was acrocentric. Also, the sex chromosome Z represents the fourth one in size and it was classified as submetacentric while, W chromosome appeared as medium size and was acrocentric. Furthermore, C-banding pattern (constitutive heterochromatin) revealed variation in their sizes and occurrence between macrochromosomes. Pairs no. 7 and 8 of autosomes exhibited unusual distribution of heterochromatin, where they appeared as entirely heterochromatic. This may be related to the origin of sex chromosomes Z and W. However, there is no sufficient evidence illustrate the appearance of entirely heterochromatic autosomes. Therefore, there is no available cytogenetic literature that describes the C-banding and karyotype of Ciconia Ciconia, so the results herein are important and may assist in cytogenetic study and evolutionary pattern of Ciconiiformes.

Resumo O cariótipo e o padrão constitutivo de heterocromatina das amostras de cegonha-branca Ciconia ciconia obtidas no lago Manzala, Dimiaat, Egito, foram descritos. As células somáticas de amostras de Ciconia ciconia possuem número diploide 2n = 68 cromossomos. Dos 68 cromossomos, 11 pares incluindo cromossomos sexuais eram macrocromossomos e os pares restantes eram microcromossomos. Dos 11 pares de macrocromossomos, os nos 1, 2, 4 e 5 eram submetacêntricos, e os pares nos 6, 7 e 8 foram descritos como metacêntricos. Além disso, o par de autossomos no 3 era subtelocêntrico, enquanto o par de autossomos no 9 era acrocêntrico. Além disso, o cromossomo sexual Z representa o quarto em tamanho e foi classificado como submetacêntrico, enquanto o cromossomo W apareceu como de tamanho médio e acrocêntrico. Além disso, o padrão de bandamento C (heterocromatina constitutiva) revelou variação em seus tamanhos e ocorrência entre macrocromossomos. Pares nos 7 e 8 dos autossomos exibiram distribuição incomum de heterocromatina, onde apareceram como totalmente heterocromáticos. Isso pode estar relacionado à origem dos cromossomos sexuais Z e W. No entanto, não há evidências suficientes para ilustrar o aparecimento de autossomos totalmente heterocromáticos. Portanto, não há literatura citogenética disponível que descreva o bandamento C e o cariótipo de Ciconia ciconia, portanto os resultados aqui apresentados são importantes e podem auxiliar no estudo citogenético e no padrão evolutivo de Ciconiiformes.

First constitutive heterochromatin characterization and Karyotype of white stork Ciconia ciconia (Aves: Ciconiidae) / Primeira caracterização constitutiva de heterocromatina e cariótipo de cegonha-branca Ciconia ciconia (Aves: Ciconiidae)

Abstract The karyotype and constitutive heterochromatin pattern of the white stork Ciconia ciconia samples obtained from Manzala lake, Dimiaat, Egypt was described. Somatic cells of Ciconia ciconia samples have diploid number 2n= 68 chromosomes. Out of 68 chromosomes, 11 pairs including sex chromosomes were macrochromosomes and the remaining pairs were microchromosomes. Of the 11 macrochromosome pairs, no.1, 2, 4 and 5 were submetacentric and pairs no. 6, 7 and 8 were described as metacentric. In addition, the autosome pair no.3 was subtelocentric, while autosome pair no.9 was acrocentric. Also, the sex chromosome Z represents the fourth one in size and it was classified as submetacentric while, W chromosome appeared as medium size and was acrocentric. Furthermore, C-banding pattern (constitutive heterochromatin) revealed variation in their sizes and occurrence between macrochromosomes. Pairs no. 7 and 8 of autosomes exhibited unusual distribution of heterochromatin, where they appeared as entirely heterochromatic. This may be related to the origin of sex chromosomes Z and W. However, there is no sufficient evidence illustrate the appearance of entirely heterochromatic autosomes. Therefore, there is no available cytogenetic literature that describes the C-banding and karyotype of Ciconia Ciconia, so the results herein are important and may assist in cytogenetic study and evolutionary pattern of Ciconiiformes.

Resumo O cariótipo e o padrão constitutivo de heterocromatina das amostras de cegonha-branca Ciconia ciconia obtidas no lago Manzala, Dimiaat, Egito, foram descritos. As células somáticas de amostras de Ciconia ciconia possuem número diploide 2n = 68 cromossomos. Dos 68 cromossomos, 11 pares incluindo cromossomos sexuais eram macrocromossomos e os pares restantes eram microcromossomos. Dos 11 pares de macrocromossomos, os nos 1, 2, 4 e 5 eram submetacêntricos, e os pares nos 6, 7 e 8 foram descritos como metacêntricos. Além disso, o par de autossomos no 3 era subtelocêntrico, enquanto o par de autossomos no 9 era acrocêntrico. Além disso, o cromossomo sexual Z representa o quarto em tamanho e foi classificado como submetacêntrico, enquanto o cromossomo W apareceu como de tamanho médio e acrocêntrico. Além disso, o padrão de bandamento C (heterocromatina constitutiva) revelou variação em seus tamanhos e ocorrência entre macrocromossomos. Pares nos 7 e 8 dos autossomos exibiram distribuição incomum de heterocromatina, onde apareceram como totalmente heterocromáticos. Isso pode estar relacionado à origem dos cromossomos sexuais Z e W. No entanto, não há evidências suficientes para ilustrar o aparecimento de autossomos totalmente heterocromáticos. Portanto, não há literatura citogenética disponível que descreva o bandamento C e o cariótipo de Ciconia ciconia, portanto os resultados aqui apresentados são importantes e podem auxiliar no estudo citogenético e no padrão evolutivo de Ciconiiformes.

Chromosomic studies in Zephyranthes citrina baker (Amaryllidaceae), a polyploid ornamental / Estudios cromosómicos en Zephyranthes citrina baker (Amaryllidaceae), un poliploide ornamental

ABSTRACT Zephyranthes citrina is an ornamental American bulbous plant used as an ornamental garden crop for the aesthetic qualities of its yellow perigonium. The objective of this work was to characterize the species by classical chromosome staining and fluorochrome banding. A sporophytic chromosome number of 2n=8x=48 chromosomes was observed, being the karyotypic formula 20 m + 26 sm + 2 st. Satellites were detected in the short arm of metacentric chromosomes 8, 9, 11 and 12, which colocalized with constitutive heterochromatin CMA+/DAPI-/0 bands. The karyotype comprised chromosome pairs with terminal constitutive heterochromatin bands that included satellites and heteromorphic clusters indicating that it is an allooctoploid. These results will be used as a tool for monitoring genetic improvement, in interspecific crosses and its progenies and in biotechnological procedures by in vitro culture.

RESUMEN Zephyranhtes citrina es una planta bulbosa americana, ornamental, utilizada en jardines por las cualidades estéticas de su perigonio amarillo. El objetivo de este trabajo fue caracterizar citogenéticamente la especie con tinción clásica convencional y bandeo cromosómico. Se observó un número cromosómico esporofítico de 2n=8x=48, siendo la fórmula cariotípica 20 m + 26 sm + 2st. Se detectaron satélites en el brazo corto de los cromosomas metacéntricos 8, 9, 11 y 12, que co-localizaron con bandas de heterocromatina constitutiva CMA+/DAPI-. El cariotipo comprendió pares de cromosomas con bandas de heterocromatina constitutivas terminales que incluyeron satélites y grupos heteromórficos que indican que es un alooctoploide. Estos resultados serán usados como herramientas en el monitoreo del mejoramiento genético, en análisis de cruzamientos interespecíficos y progenies y en procedimientos biotecnológicos de cultivo in vitro.

Comparative cytogenetic analysis of two grasshopper species of the tribe Abracrini (Ommatolampinae, Acrididae)

The grasshopper species Orthoscapheus rufipes and Eujivarus fusiformis were analyzed using several cytogenetic techniques. The karyotype of O. rufipes, described here for the first time, had a diploid number of 2n = 23, whereas E. fusiformis had a karyotype with 2n = 21. The two species showed the same mechanism of sex determination (XO type) but differed in chromosome morphology. Pericentromeric blocks of constitutive heterochromatin (CH) were detected in the chromosome complement of both species. CMA3/DA/DAPI staining revealed CMA3-positive blocks in CH regions in four autosomal bivalents of O. rufipes and in two of E. fusiformis. The location of active NORs differed between the two species, occurring in bivalents M6 and S9 of O. rufipes and M6 and M7 of E. fusiformsi. The rDNA sites revealed by FISH coincided with the number and position of the active NORs detected by AgNO3 staining. The variability in chromosomal markers accounted for the karyotype differentiation observed in the tribe Abracrini.

Hidden heterochromatin: characterization in the Rodentia species Cricetus cricetus, Peromyscus eremicus (Cricetidae) and Praomys tullbergi (Muridae)

The use of in situ restriction endonuclease (RE) (which cleaves DNA at specific sequences) digestion has proven to be a useful technique in improving the dissection of constitutive heterochromatin (CH), and in the understanding of the CH evolution in different genomes. In the present work we describe in detail the CH of the three Rodentia species, Cricetus cricetus, Peromyscus eremicus (family Cricetidae) and Praomys tullbergi (family Muridae) using a panel of seven REs followed by C-banding. Comparison of the amount, distribution and molecular nature of C-positive heterochromatin revealed molecular heterogeneity in the heterochromatin of the three species. The large number of subclasses of CH identified in Praomys tullbergi chromosomes indicated that the karyotype of this species is the more derived when compared with the other two genomes analyzed, probably originated by a great number of complex chromosomal rearrangements. The high level of sequence heterogeneity identified in the CH of the three genomes suggests the coexistence of different satellite DNA families, or variants of these families in these genomes.

Cytogenetic analyses of two Curimatidae species (Pisces; Characiformes) from the Paranapanema and Tietê Rivers

Cytogenetic analyses were performed in two Curimatidae species (Steindachnerina insculpta and Cyphocharax modesta) from the Paranapanema and Tietê Rivers (São Paulo State, Brazil), showing a karyotype composed of 54 meta-submetacentric chromosomes in both species. Silver- and chromomycyn-staining and fluorescent in situ hybridization (FISH) using a 18S rDNA probe indicated that the nucleolar organizer regions (NORs) of both species are localized in the terminal region of the long arm of two metacentric chromosomes. Although a single NOR system was evidenced in both analyzed species, S. insculpta and C. modesta presented the nucleolar organizer regions in distinct chromosome pairs, indicating that these cistrons can be considered cytogenetic markers. Variation on the amount and distribution of the constitutive heterochromatin (C-bands) could also be detected between the two species - while S. insculpta presented few heterochromatic blocks, intensely stained C-bands were evidenced in C. modesta specially in the terminal region of the long arm of the NOR-bearing chromosomes. Although most Curimatidae species have been characterized by homogeneous karyotypes, isolated populations could be established under different environmental conditions leading to karyotype micro-structure variations specially related to the NORs localization and C-banding distribution. The obtained data were useful for the cytogenetic characterization and differentiation of S. insculpta and C. modesta and could be used in evolutionary inferences in the Curimatidae group.

Análises citogenéticas foram realizadas em duas espécies de Curimatidae (Steindachnerina insculpta e Cyphocharax modestus) provenientes dos rios Paranapanema e Tietê (Estado de São Paulo, Brasil), evidenciando um cariótipo composto por 54 cromossomos meta-submetacêntricos em ambas as espécies. Coloração com nitrato de prata e cromomicina e hibridação in situ fluorescente (FISH), utilizando uma sonda de DNAr 18S, mostraram que as regiões organizadoras de nucléolos (RONs) de ambas as espécies estão localizadas na região terminal do braço longo de dois cromossomos metacêntricos. Embora as espécies analisadas tenham apresentado um sistema de RONs simples, S. insculpta e C. modesta apresentaram as regiões organizadoras de nucléolos em distintos pares de cromossomos, indicando que estes cístrons podem ser considerados marcadores citogenéticos. Variação na quantidade e distribuição de heterocromatina constitutiva (bandas C) também pôde ser detectada entre as duas espécies - enquanto S. insculpta apresentou poucos blocos heterocromáticos, bandas C intensamente coradas foram evidenciadas em C. modesta especialmente na região terminal do braço longo dos cromossomos portadores de RONs. Embora a maioria das espécies de Curimatidae seja caracterizada por cariótipos homogêneos, populações isoladas podem ter se estabelecido sob condições ambientais distintas, levando à ocorrência de variações na micro-estrutura cariotípica especialmente relacionadas à localização das RONs e à distribuição das bandas C. Os dados obtidos mostraram-se úteis para caracterização e diferenciação citogenética de S. insculpta e C. modesta e podem ser utilizados em inferências evolutivas no grupo Curimatidae.

Astylus variegatus (Coleoptera, Melyridae): Cytogenetic study of a population exposed to agrochemical products

In this work we describe the cytogenetic analyses performed in specimens of Astylus variegatus (Germar, 1824) collected in two localities: one area of natural vegetation and one of agricultural crops, where agrochemical products were used. Astylus variegatus had karyotypes with 2n(male) = 16+Xy p and 2n (female) = 16+XXp, with exclusively metacentric chromosomes. Pachytene spermatocytes showed synapsed autosomal bivalents and non-associated sex chromosomes. In diplotene, the autosomal bivalents exhibited one or two terminal chiasmata and the Xy p had a typical parachute configuration. In meiotic cells of some specimens, an extra chromosome, interpreted as a B chromosome, was observed. C-banding showed constitutive heterochromatin in the pericentromeric region of all chromosomes, with the exception of the y p. Silver nitrate staining revealed one nucleolus organizer region (NOR) on the terminal region of the short arm of the second autosome pair. Silver staining of meiotic cells confirmed the NOR pattern detected in mitotic cells and revealed an argentophilous material on the Xy p. A cytogenetic comparison between the two populations of A. variegatus showed a statistically significant divergence (chi2 = 117.10; df = 1) in the number of aneuploid cells and a higher frequency of B chromosome in the population exposed to agrochemicals.

An Increased Incidence Of C-Band Heteromorphism In Hereditary Breast Cancer Patients and Their Healthy Blood Relatives An Indian Experience.

Healthy blood relatives (HBR) of the hereditary breast cancer (HBC) patients are considered to be at higher risk to develop cancer. However, all of them do not suffer from same. This may indicate the possibility of association with genetic polymorphism among them. We have studied this genetic polymorphism in terms of C-band heteromorphism among 11 HBC patients, 36 HBR and results were compared with 22 control females. Significantly higher incidence (p < 0.001) of C-band heteromorphism has been observed among the HBC patients and their HBR as compared to the control females. At the same time, however, the difference in incidence of C-band heteromorphism among HBC patients and their HBR were not statistically significant. The findings indicate possibilities of (i) an association between C-band heteromorphism and hereditary breast cancer, and (ii) C-band heteromorphism may be one of the important factors conferring HBR at an elevated risk to develop the breast cancer.