Caryologia, Vol. 55, no. 1, 2002

Caryologia, Vol. 55, no. 1, 2002, 01-04

Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, 36571-000 Brazil.

Abstract - It was analyzed the interaction of B chromosomes with large knobs on

chromosomes 3 and 9 in maize (high loss phenomenon), determining the frequency

of concomitant breaks on these chromosomes, scoring for endosperm

markers. Simultaneous loss of chromosomes 3 and 9 had a value 2.2 times higher

than that expected if considering independent events. It seems that breaks

induced by B chromosomes are clustered in specific spores. From the four different

types of sperm nuclei derived from breakage of the two bridges of knobbed

chromosomes 3 and 9, at the same or opposite sides of the equatorial plate, at the

second microspore mitosis, only one of them can be correctly scored in the

endosperm as doudle loss. Two are scored as single loss, since one translocated

chromosome goes to the endosperm and the other to the embryo and one sperm

nucleus has two normal chromosomes in the endosperm hence the dicentric chromosome

goes to the embryo. So, when we score for markers in the endosperm,

the observed frequency of simultaneous loss is only one fourth the actual frequency.

Caryologia, Vol. 55, no. 1, 2002, 05-14

Nucleolar changes in malpighian tubules cells of

Rhodnius prolixus during starvation

PATRÍCIA MARTINS CASSEB-HASSAN, ADRIANA BARBOSA SANTOS2 and MARIA TERCÍLIA VILELA DE

AZEREDO-OLIVEIRA1, *

1 Department of Biology.

2 Department of Computation Science and Statistics - Biosciences, Languages and Exact Sciences Institute, São José do Rio

Preto, University of the State of São Paulo (UNESP), CEP 15054-000, São José do Rio Preto, SP, Brazil.

Abstract - This study focused on nuclear and nucleolar area changes in Malpighian

tubule cells of Rhodnius prolixus, an hematophagous insect, vector of Chagas‘

disease. Male and female adult insects were dissected after a 28-day starvation

period, as well as insects which had been fed again after a 30-day starvation period.

Malpighian tubules were fixed and silver stained. In both, males and females,

nucleolar fusions and regions of nucleolar corpuscles were observed to be

differentially impregnated by silver during feeding stress. In the males and females

that were fed again, nucleolar corpuscles were partially fusioned, indicating

a slight recovery upon the 30-day starvation period. The changes observed in

the nucleolar phenotype and in both nuclear and nucleolar areas indicated that,

as a result of stress, a more intense, compensatory activity occurred to supply the

metabolic rate. The mechanism of this phenomenon may be associated to the decondensation

and activation of chromatin that carries rDNA in order to increase

rRNA transcription, and,consequently, protein synthesis.

Caryologia, Vol. 55, no. 1, 2002, 15-19

Meiotic studies in Lygaeus alboornatus Blanchard

1852 (Heteroptera, Lygaeidae, Lygaeinae)

MARÍA JOSÉ BRESSA1, ALBA G. PAPESCHI2 and MARCELO L. LARRAMENDY1, *

1 Laboratorio de Citogenética y Cátedra de Citología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de

La Plata, Calle 37 Nro. 668 7mo “B”, 1900 La Plata, Argentina.

2 Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires,

Argentina.

Abstract - The subfamily Lygaeinae comprises 58 genera with about 500 species

distributed world-wide. Despite the great biodiversity of the taxon, cytogenetic

data of the group is scarce. To date, only 26 species belonging to 12 genera have

been cytogenetically described. As it is the rule for the order Heteroptera, all the

species possess holokinetic chromosomes, and a pre-reductional type of meiosis,

namely at anaphase I the autosomal bivalents divide reductionally while the sex

chromosomes are achiasmatic and divide equationally. Available data reveal that

all the Lygaeinae are characterised by a modal diploid number of 14 and an

XY/XX sex chromosome determining system. In the present study the male meiotic

development of Lygaeus alboornatus from Argentina is analysed. The results

demonstrate that the species, though sharing the basic chromosomal features

from Lygaeinae, has a diploid number of 12 (10+XY), being this chromosome

number the lowest reported so far for the subfamily.

Caryologia, Vol. 55, no. 1, 2002, 21-25

Pinus laricio Poir. and P. leucodermis Antoine:

karyotype analysis in Calabrian populations

(Southern Italy)

GIULIANO CESCA and LORENZO PERUZZI*

Orto Botanico, Università della Calabria, 87030 Arcavacata di Rende,Cosenza, Italy.

Abstract – Two pine tree species, distinctive of Calabria’s mountain landscape,

were studied karyologically. The karyotypes of the two species, 2n = 24, differ

both in their morphology and particularly in the number of secondary constrictions

occurring: 14 in Pinus laricio Poir. and 6 in P. leucodermis Antoine. Systematic

individuality of the latter from P. heldreichii Christ is confirmed. Separation

of P. laricio from P. nigra Arnold is proposed. A new taxonomic conspectus

is presented for Calabrian P. laricio: Pinus laricio subsp. calabrica (Loud.)

Cesca et Peruzzi comb. et stat. nov.

Caryologia, Vol. 55, no. 1, 2002, 27-35

Chromosome contribution to Andean Polyploid

Species of Senecio (Asteraceae), from Argentina

MARIANA G. LÓPEZ1, *, ARTURO F. WULFF1, 2 and CECILIA C. XIFREDA3, 4

1 Laboratorio de Citogenética y Evolución, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales,

Universidad de Buenos Aires. Intendente Güiraldes y Costanera Norte, 1428 Buenos Aires, Argentina.

2 Member of the Carrera del Personal de Apoyo (CONICET).

3 Laboratorio de Etnobotánica y Botánica Aplicada, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La

Plata. Paseo del Bosque s/n, 1900 La Plata, Argentina.

4 Member of the Carrera del Investigador Científico (CIC-PBA).

Abstract - Meiotic chromosome numbers were determined and observations of

meiotic behavior were made in six species and two hybrid specimens of Senecio

L. (Asteraceae).

Two different numbers were found: 2n=4x=40 in S. pogonias Cabr., S. ragonesei

Cabr., S. sectilis Griseb. and S. viridis Phil. var. radiatus R. E. Fr. and 2n=8x=80

in S. subulatus D. Don. var. subulatus and in S. uspallatensis Hook. et Arn.; the

latter showed the same chromosome number previously reported. The chromosome

number of the hybrid individuals was 2n=4x=40, being their putative parents

S. ragonesei and S. sectilis. B chromosomes were found in some individuals

of S. pogonias, S. sectilis, S. subulatus var. subulatus and S. uspallatensis.

Many meiotic irregularities such as bridges, fragments, laggard chromosomes,

micronuclei and cellular fusion were observed. The results are analyzed in relation

to the persistence and success of these polyploids, and the speciation mechanisms

operating within this group are discussed.

Caryologia, Vol. 55, no. 1, 2002, 37-45

Chromosomal polymorphism in Serrasalmus spilopleura

Kner, 1858 (Characidae, Serrasalminae) from Central

Amazon Basin

LIANO CENTOFANTE1, *, JORGE IVAN REBELO PORTO2 and ELIANA FELDBERG2

1 Universidade Federal de São Carlos, Departamento de Genética e Evolução, Laboratório de Citogenética Animal,

Via Washington Luiz, Km 235, Cx. Postal 676, 565-905, São Carlos, SP, Brasil.

2 Instituto Nacional de Pesquisas da Amazônia, Coordenação de Pesquisas em Biologia Aquática, Cx. Postal, 478, 69.011-970,

Manaus, Amazonas, Brasil.

Abstract - Cytogenetic studies were performed in Serrasalmus spilopleura, a piranha

species, from three sampling sites in the Central Amazon basin: 1. Catalão;

2. Manacapuru, 3. Itacoatiara. All specimens displayed 2n=60 chromosomes and

no sexual chromosomal heteromorphism was found. However, by considering

the karyotypic formula, three cytotypes were identifyed: cytotype A consisted

of 24M+20SM+4ST+12A, and was the most common being found in all three

sampling sites; cytotype C consisted of 23M+21SM+4ST+12A, was found only

in Catalão and differ from cytotype A by the presence of a heteroziguous inversion

in the first chromosome pair and a distal heterocromatinization in the

long arm of this same pair, probably caused by the rearrangement or due to a

chromosomal adjustment; cytotype D consisted of 24M+20SM+4ST+12A, was

found only in Manacapuru and differ from cytoytpe A by a heteroziguous size

polymorphism on the second chromosome pair, probably due to a translocation.

C-banding revealed the same constitutive heterochromatin pattern for the three

cytotypes except for the chromosome pair that underwent pericentric inversion

(cytotype C) which possessed different heterochromatic blocks. Analysis in the

number of active nucleolar organizing regions (NORs) revealed no differentiation

among cytotypes and NOR-bearing chromosomes varied from 10–12 acrocentric

chromosomes.

Caryologia, Vol. 55, no. 1, 2002, 47-53

Mercury-induced DNA variations in the genome

of Posidonia oceanica Delile

P. MAESTRINI1, T. GIORDANI1, E. POLIZZI1, L. NATALI1, B.E. MASERTI2, E. BALESTRI3 and A. CAVALLINI1, *

1 Dipartimento di Biologia delle Piante Agrarie della Università, Sezione di Genetica, Via Matteotti 1/B, I-56124 Pisa.

2 Consiglio Nazionale delle Ricerche, Istituto di Biofisica, Area della Ricerca, Via Moruzzi 1, 56010 Ghezzano, San Giuliano

Terme, Pisa.

3 Dipartimento di Scienze dell’Ambiente e del Territorio, Via Volta 6, I-56100 Pisa, Italy.

Abstract - Posidonia oceanica Delile is a marine phanerogam, largely spread

in the mediterranean basin, where forms large prairies. Since this plant can live

on mercury rich sites, this species is used as a biological indicator of mercury

contamination. With the aim to study genotoxic effect of mercury on this plant

species, we analyzed genomic DNA of plants treated with 1 μM mercury for 15

days in aquarium. At the end of this treatment, plants accumulated elevated

mercury concentrations in their leaves. After ultracentrifugation in a Cs2SO4

gradient, P. oceanica genomic DNA profile showed, beside the main peak, a

light shoulder containing A-T rich DNA sequences. This shoulder is missing

in the profile of DNA isolated from mercury treated plants. Gradient slot-blotting

and hybridization with these variable DNA families, labelled with digoxigenin,

indicated that these DNA sequences are at least partially lost in mercury

treated plants. It was determined, by genomic DNA slot-blotting and hybridization,

that DNA loss of A-T rich DNA sequences (forming the light

shoulder) was around 48%.

Caryologia, Vol. 55, no. 1, 2002, 55-62

Heterochromatin distribution in selected taxa of the

42-chromosomes Orchis s. l. (Orchidaceae)

S. D’EMERICO1, *, S. COZZOLINO2, G. PELLEGRINO3, D. PIGNONE4 and A. SCRUGLI5

1 Dipartimento di Biologia e Patologia Vegetale, Università di Bari, Via Orabona, 4 I-70125 Bari, Italy.

2 Orto Botanico, Università Federico II-Napoli.

3 Dipartimento di Ecologia, Università della Calabria-Rende.

4 C.N.R. Istituto del Germoplasma, Bari.

5 Dipartimento di Scienze Botaniche, Università di Cagliari.

Abstract - In six 42-chromosomes taxa belonging to genus Orchis s. l. heterochromatin

location and distribution and staining properties were analysed by

means of C-banding and of the fluorochromes 4’-6-diamidino-2-phenylindole-

2HCl (DAPI) and Hoechst 33258. Most species could be distinguished on the basis

of heterochromatin amounts and distribution. In the species O. mascula and

O. provincialis most DAPI-positive sites did not co-localize with C-bands. DAPI

revealed bright fluorescence at telomeric or subtelomeric regions of numerous

chromosomes of O. mascula and particularly large/bright blocks at the telomeres

of O. provincialis. In O. x penzigiana (Orchis mascula ssp. ichnusae x O. provincialis)

overall heterochromatin distribution followed that of the parental species.

In Neotinea group all DAPI positive bands co-localize with C-bands, but have different

distribution in the taxa analysed. Present and literature data indicate a high

level of plasticity of heterochromatin organization in Orchis s. l., and suggest evolutionary

pathways in agreement with recent molecular data.

Caryologia, Vol. 55, no. 1, 2002, 63-72

Cytological investigations in some important tree

species of Rajasthan II. Male meiosis studies in the

genus Anogeissus (DC.) Guill., Perr. and A. Rich.

ARUN KUMAR and S. RAMA RAO*

Cytogenetics and Molecular Biology Laboratory, Department of Botany, J.N. Vyas University, Jodhpur-342005, India.

Abstract - Male meiosis studies were under taken in seven different accessions

belonging to three species of Anogeissus, an important hard wood tree of arid

and semiarid regions of western India. Data collected on chromosome associations,

chiasma analysis and distribution pattern of chromosomes at anaphase I/II

confirmed that the genus Anogeissus is monobasic in origin (n=12) and its speciation

is mostly helped by genetic/genic alternations, B-chromosomes, and distally

localized recombinations followed by extensive out breeding. Virtually polyploidy

and structural changes of chromosomes (interchanges, inversions etc.)

played no role in its evolution.

Caryologia, Vol. 55, no. 1, 2002, 73-79

Synaptonemal complex analysis in the fish species

Piaractus mesopotamicus and Colossoma macropomum,

and in their interspecific hybrid

VERA HABDA DOS SANTOS1, FAUSTO FORESTI1, CLAUDIO OLIVEIRA1, *, LURDES FORESTI DE ALMEIDATOLEDO2,

SILVIO DE ALMEIDA TOLEDO-FILHO2 †, and GERALDO BERNARDINO3

† In memoriam.

1 Depto. de Morfologia, Instituto de Biociência, UNESP, 18618-000, Botucatu, SP, Brazil.

2 Depto. de Biologia, Instituto de Biociência, USP, São Paulo, SP, Brazil.

3 Centro de Pesquisa e Treinamento em Aqüicultura, IBAMA, Pirassununga, SP, Brazil.

Abstract - The surface-spreading technique for visualization of whole cell synaptonemal

complex (SC) complements was employed to study the chromosome

synapsis in spermatocytes of P. mesopotamicus, C. macropomum and in their interspecific

hybrid (“tambacu”) with the main objective to analyze possible errors

in chromosome pairing that could result in hybrid sterility. SC analysis showed

that the parental species P. mesopotamicus and C. macropomum have 27 bivalents

homogeneously synapsed. The SC in spermatocytes from the hybrid “tambacu”

showed gross meiotic configurations in all cells analyzed. The spermatocytes exhibited

a few chromosomes or well synapsed chromosome segments, while many

chromosome segments did not have any synapsis. This result, allied to other genetical

and cytogenetical evidence, reinforces the hypothesis that the hybrid

“tambacu” is sterile. Further studies involving other aspects, such as behavior

and physiology, should be conduced before the introduction of these hybrids

in rivers and lakes.

Caryologia, Vol. 55, no. 1, 2002, 81-89

Karyotypic study in some Iranian species and

populations of Tulipa L. (Liliaceae)

SHEIDAI MASOUD*, ZOGAGI-FAR SHIRIN, KHANAFSHAR SHADI and ZEHZAD BAHRAM

Biology Department, Shahid Beheshti University, Evin, Tehran, Iran.

Abstract - Karyotypic studies were performed on 12 species/ populations of Iranian

tulips for the first time. The species/ populations possessed 2n = 2x = 24 chromosome

number but varied in details of karyotype including type of chromosomes,

karyotype symmetry and number of SAT-chromosomes and differed significantly

in total chromatin length as well as length of chromosome arms. A pair

of heteromorph chromosomes occurred in T. humilis. The use of karyotypic data

in taxonomy of the genus Tulipa L. is discussed.

Caryologia, Vol. 55, no. 1, 2002, 91-98

Chromatin organisation and computer aided

karyotyping of Triticum durum Desf. cv. Timilia

G. VENORA1, S. BLANGIFORTI1, M. RUFFINI CASTIGLIONE2, D. PIGNONE3, F. LOSAVIO3 and R. CREMONINI2, *

1 Stazione Sperimentale di Granicoltura per la Sicilia, Caltagirone, Italy.

2 Dipartimento di Scienze Botaniche, Università di Pisa, Pisa, Italy.

3 Istituto del Germoplasma CNR Bari, Italy.

Abstract - The tribe Triticeae includes three cereal genera Secale, Hordeum and

Triticum and because of their economical and agronomical importance, the relationships

among species on the tribe have been extensively investigated. The wild

wheat relatives are an important source of genetic variation for cultivated species

and wheat is an important crop of the mediterranean region. Banding pattern of

metaphase chromosomes and nuclear DNA content in root meristematic cells of

an old sicilian landrace “Timilia” were determined. Microdensitometric evaluation

of nuclear absorption at different thresholds of optical density indicates the

organization of chromatin in the interphase nuclei. Chromosome morphometric

data, karyotype simmetry, the TF% values and Syi indices were determined. The

results are compared with the data of other durum wheat varieties as Capeiti and

Simeto.