Karyological study of one charadriiform and two passerine Indian birds

The karyotypes of one charadriiform bird, Himantopus himantopus himantopus (Linnaeus) (Recurvirostridae) and two passerine birds, Chloropsis cochinchinensis jerdoni (Blyth) (Irenidae) and Melophus lathami (Gray) (Emberizidae), hithertho cytologically unknown have been studied. The diploid chromosome number (2n) is 82 ± in H. h. himantopus and 80 ± in both C. c. jerdoni and M. lathami. The Z and W chromosomes were identified except in H. h. himantopus. C-banding analysis in C. c. jerdoni shows almost the entire W chromosome and the short arm of the 5th chromosome to be completely heterochromatic. Possible karyological relationships among congeneric and confamilial species are discussed.     

Chromosome complement, C-banding and Ag-NOR in Gymnammodytes cicerelus (Ammodytidae, Perciformes)

The karyotype of a sandlance species, Gymnammodytes cicerelus , comprises: seven meta-centric, seven submetacentric and nine subtelocentric-acrocentric pairs (2 n =46, FN=74). The C-bands appear in paracentromeric and telomeric areas of most chromosomes and the NOR regions, in two pairs of larger chromosomes. All these characteristics indicate that a large number of rearrangements seem to have been involved in the karyotype evolution of this species.     

Chromosome numbers,C-banding patterns and sperm of some ladybird species from Central Europe (Coleoptera,Coccinellidae)

C-banded karyotypes were studied in the males of seven ladybird species from the subfamily Coccinellinae, viz. Adonia variegata (Goeze), Tythaspis sedecimpunctata (L.), Coccinella septempunctata (L.), Calvia decemguttata (L.), Calvia quatuordecimguttata (L.), Propylea quatuordecimpunctata (L.), Phyllobora vigintiduopunctata (L.). All the species, with the exception of Tythaspis sedecimpunctata (L.), possess 2n = 20, n(male) = 9 + Xy(p). Tythaspis sedecimpunctata (L.), however, has 2n = 24, n(male) = 11+Xy. The examined karyotypes show only a paracentromeric position of constitutive heterochromatin in all autosomes and the sex chromosome X, while the y heterochromosome is dot-like and wholly euchromatic. Successive stages of spermiogenesis were analysed.     

Chromosome numbers of some Indian moths

Cytological investigations in forty-five species of Indian moths belonging to ten families (Tinaeidae, Limacodidae, Thyrididae, Pyralididae, Lasiocampidae, Saturnidae, Sphingidae, Noctuidae, Lymantriidae, Hypsidae) of Lepidoptera revealed haploid chromosome numbers varying from 12 to 31, the latter number being predominant (in 26 species). Their haploid chromosome numbers at metaphase I and II are stated in a table.     

Chromosome relationships in the genus Blennius (Blenniidae Perciformes) C-banding patterns suggest two karyoevolutional pathways

The karyotypes of the Mediterranean blenniid species: Blennius gattorugine, B. ponticus incognitus, B. pavo, B. sanguinolentus, B. galerita, B. trigloides and B. pholis were analyzed by means of conventional, silver staining and C-banding techniques. All have shown 2n=48, except B. pholis with 2n=46, while the NF varies from 54 to 72. Only two NORs, in terminal position on the short arms of the carrier pair, were detected in all species. These regions have proved to be structurally polymorphic in four species. Two markedly different C-banding patterns lead us to separate the species into two different karyoevolutionary categories, whose taxonomic and specialization implications are discussed.     

Chromosome banding pattern conservatism in birds and nonhomology of chromosome banding patterns between birds,turtles, snakes and amphibians

The G-banded karyotypes of 4 species of birds representing the orders Galliformes, Columbiformes and Musophagiformes were compared. Banding pattern homology between orders was limited t 5o 5 major chromosome arms and the Z chromosome. Even in these major chromosome arms pericentric and paracentric inversions produced alteration of the banding pattern sequences. Addition of constitutive heterochromatin was responsible for changes in banding patterns in the Z chromosome. The chromosome banding patterns of an emydid turtle, Terrepene carolina, 5 species of boid snakes of the genera Liasis, Acrantophis, and Sanzinia and the African clawed-frog. Xenopus muelleri, were also compared to the bird chromosome banding patterns. No homology was observed between any of these major groups: bird, snake, turtle, amphibian. However, intergroup homology was apparent. - The data obtained do not support reports of broad interordinal direct homology of the macrochromosomes of birds and refutes the idea of a primitive bird karyotype with 3 pairs of "Agroup' chromosomes and 3 pairs of "B group' chromosomes. - The major mechanisms responsible for chromosome evolution in birds appear to be centric and tandem fusions, paracentric and pericentric inversions, and addition or deletion of heterochromatin.     

Functional morphology of the tongue muscles of some Indian insect-eating birds

In the complex feeding apparatus of birds, the tongue muscles also play an important role like the jaw muscles. Among the passerine birds, the tongue muscles exhibit greater structural uniformity than the jaw muscles. The elaborate system of extrinsic tongue musculature brings about all necessary movements of the tongue. The intrinsic tongue musculature in all the birds studied is extremely weak and reduced. The principal tongue muscles are better developed in Turdoides and Copsychus than in the other birds. However, in Orthotomus, Anthus, Dicrurus, and Merops, some of the tongue muscles are quite well developed, perhaps compensating for the deficiencies of the other muscles. The origin of M. branchiomandibularis posterior from the outer mandibular ramus in Orthotomus, Dicrurus, and Merops is remarkable, but its occurrence may not be unusual among the passerine birds. Some variations are also observed in the origin and insertion of M. genioglossus in Turdoides, Copsychus, and Anthus. The correlations between the structures and functions of the tongue muscles are not always possible without considering the synergistic actions of the other muscles.     

毛百合根尖染色体Giemsa C-带分析

本研究利用Giemsa C-带方法对毛百合(Lilium dahuricum Ker-Gawl)根尖染色体进行了分析。研究结果表明毛百合试管苗的染色体倍性变异丰富,染色体倍性变异包括二倍体(2n=2×=24)、三倍体(2n=3×=36)、四倍体(2n=4×=48)到六倍体(2n=6×=72)。对二倍体毛百合的C-带结果进行分析,其带型公式为:2n=2×=24=2CI++2CI+T+T++6I+2I++2I++2I+T++2I+T++2I+T++2T++2T+。每条染色体上都显示出显著的特征带,而且带纹的深浅差异明显。强带主要集中在长短臂上。因此,GiemsaC-带方法可以将毛百合(L.dahuricum)的每条染色体区分开。     

四种蚤染色体组型及C分带研究

本文首次在国内报道了住鼠客蚤、猫栉首蚤指名亚种、人蚤和秃病蚤蒙翼亚种的染色体组型和Ｃ分带研究结果。１、印鼠客蚤２ｎ＝１８＝１０ｍ＋６ｓｍ＋２ｓｔ,ＸＸ／ＹＹ．２猫蚤２ｎ＝１２＝１０ｍ＋２ｓｍ,ＸＸ／ＹＹ,核型特点为２号染色体的多态性和３号与６号染色体间发生不对称性易位。３、人蚤核型特点是：（１）染色体数目多态现象,变异范围８－１２,以９－１２者多见,ＸＸ／ＹＹ性染色体决定机制。（２）染色体结构重组     

Giemsa C-banding patterns in Aedes (Stegomyia) mosquitoes

Chromosomes from gonads of 14–24 h old pupae of nine species of Stegomyia mosquitoes have been examined using the Giemsa C-banding technique. The species studied were Aedes albopictus, A. polynesienis, A. scutellaris, A. alcasidi, A. seatoi, A. pseudalbopictus, A. melallicus, A. annandalei and A. vittatus. The diploid chromosome number of all species is six. All species possess C-bands in the centromeric regions of each of the three pairs of chromosomes. Besides, an intercalary C-band is present on the female determining (=m) chromosome but absent from the male—determining (= M) chromosome of all species except A. vittatus. In A. vittatus, the m and M chromosomes possess a terminal C-band. Thus, the nine species of Aedes analysed showed two distinct patterns of C-banding. —The evolution of heterochromatin patterns in various species is also discussed. The Giemsa C-banding technique should prove useful in studies of chromosomal speciation in culicine mosquitoes.     

Variability of C-banding patterns in Japanese quail chromosomes.

Observations were made of the C-banding patterns in several cells from 182 Japanese quail embryos to detect presence of stable variants. Each of the eight largest autosomes contains a C-band at the centromeric region. The short arm of autosome 8 is C-band positive, as is the entire W chromosome. The Z chromosome consistently contains an interstitial C-band in the long arm and a less prominent one in the short arm. Distinct variants of chromosome 4 and the Z chromosome were observed. In the Z chromosome a C-band at the terminal region of the short arm was markedly elongated in some embryos. Likewise, the short arm of chromosome 4 was much more prominent in one or both of the homologues in some embryos. Most of the microchromosomes contain a prominent C-band. The heteromorphisms are useful chromosome markers to detect the origins of heteroploidy in early embryos.     

Vigilance and scanning patterns in birds

We present a new approach to the analysis of scanning patterns in feeding birds. We estimate the probability of a bird detecting a predator from the frequency distribution of inter-scan intervals and the proportion of time spent scanning. This method avoids, several unrealistic assumptions implied in earlier analyses of vigilance data, and can accommodate predators attacking randomly or using prey behaviour to time an attack. The practical application of this approach is illustrated using data for feeding and vigilance in the ostrich (Struthio camelus). The analysis is discussed with reference to the hunting tactics of predators and Pulliam's (1973) model of feeding and vigilance in birds.     

Chromosome inversions in Indian Drosophila melanogaster

Ten laboratory stocks of Drosophila melanogaster initiated from females collected in different localities in India were analysed for chromosome inversions. Six inversions were found to be present, three in 2L, one in 2R, one in 3L and one in 3R. Out of these six inversions, three are new and are being reported for the first time. Furthermore, this is the first report of inversion polymorphism in Indian D. melanogaster. The persistence of inversion polymorphism in our laboratory stocks of D. melanogaster which were maintained for more than one year under laboratory conditions, suggests some heterotic advantage of inversion heterozygotes.     

宜昌百合根尖染色体C-带分析

利用Giemsa C-带方法对宜昌百合（Lilium leucanthum(Baker) Baker）进行研究。结果表明：宜昌百合（L. leucanthum）的染色体数目为2n＝2x=24,单套染色体的条带总数目为21条。其带型公式为：2n＝24＝6C+2CI+2I+2CI⁺+2CI⁺+4I⁺+2I⁺+2T⁺+2I+S。宜昌百合（L. leucanthum）每条染色体上都显示出显著的特征带,且带纹的深浅差异明显。宜昌百合（L. leucanthum）的强带主要集中在着丝点及附近区域。通过Giemsa C-带方法可以将宜昌百合（L. leucanthum）的每条染色体区分开。     

黄颡鱼染色体的C-带、Ag-NORs、荧光带和复制带显带的研究

采用Giemas染色、C-带、Ag-NORs、荧光染色和复制带显带的技术对黄颡鱼染色体进行了研究。结果表明, 黄颡鱼只有部分的染色体呈现阳性C-带, 可分为三类, 其中NORs区是染色最深、染色面积最大的区域, 为深染居间C-带。其Ag-NORs位于m5q末端。CMA3染色显示 NORs区呈现出明亮的荧光。中复制染色体上着丝粒区、端粒区和居间区浅染。发现核仁缢痕、深染居间C-带、Ag-NORs、CMA3明亮区和中复制带浅染NORs区位置基本一致, C-带阳性区和中复制带浅染区具有对应性。 Abstract　Metaphase chromosomes of Pelteobagrus fulvidraco were analyzed by means of Giemsa staining, C-banding, Ag-NORs, fluorochrome staining and replication banding. Only parts of chromosomes showed C-band positive, the C-band heterochromatin was located in three regions. The NORs-bearing chromosomes had the largest and strongest C-bands. The long arms of chromosome pair 5 were the regions showing positive labeling with Ag-staining. Fluorochrome CMA3positively stained the NORs. In mid-period, negative replication bands were located in the centromere, the terminal and interstitial regions of the chromosomes. The distributions of secondary ?constri-ctions, positive C-bands, Ag-NORs, positive fluorescence bands and negative replication bands of mid-period were coincident.