Cytogenetic characterization of two species of Frieseomelitta Ihering, 1912 (Hymenoptera, Apidae, Meliponini)

The cytogenetic analysis of Frieseomelitta dispar and F. francoi revealed the chromosome numbers 2n = 30 and n = 15 and a karyotypic formula 2K = 4M+2M(t)+4A+20A(M). The number of chromosomes observed was consistent with those reported for other Frieseomelitta species. The occurrence of the M(t) chromosome and other features of the karyotype formulae suggest a close relationship between F. dispar, F. francoi and F. varia. Nevertheless, it was possible to differentiate the karyotypes of the species by DAPI/CMA(3) staining, which revealed GC-rich regions on two chromosome pairs of F. dispar: one acrocentric and one pseudoacrocentric. In F. francoi, the same kinds of regions were observed on a pair of metacentrics and on a pair of acrocentrics. Our analysis also confirmed the chromosome number conservation in Frieseomelitta and suggests that infrequent pericentric inversion could constitute a synapomorphy for the group including F. dispar, F. francoi, and F. varia.     

New Neotropical species of Chimarra (Trichoptera, Philopotamidae)

Ten new Neotropical species of Chimarra are described in the subgenera Chimarra, Chimarrita, and Otarrha. New species in the subgenus Chimarra include, in the Chimarra ortiziana group: Chimarra calorisp. n. (southeastern Brazil) and Chimarra onchyrhinasp. n. (Venezuela); in the Chimarra picea group: Chimarra inchoatasp. n. (Venezuela), Chimarra nicehuhsp. n. (Venezuela), and Chimarra sunimasp. n. (Colombia); and in the Chimarra poolei group: Chimarra caucasp. n. (Colombia) and Chimarra desiraesp. n. (Bolivia). New species in the subgenus Chimarrita include, in the Chimarra simpliciforma group: Chimarra curvipenissp. n. (SE Brazil) and Chimarra latiforcepssp. n. (SE Brazil). A single new species in the subgenus Otarrha is also described: Chimarra soroasp. n. (Cuba). Males and females for all of the new species are illustrated, except for Chimarra desirae, for which female specimens were unavailable. Additionally, the female of Chimarra (Chimarrita) camella, which was previously unknown, is illustrated.     

Alcohol dehydrogenase activities and ethanol tolerance in Anastrepha (Diptera, Tephritidae) fruit-fly species and their hybrids

The ADH (alcohol dehydrogenase) system is one of the earliest known models of molecular evolution, and is still the most studied in Drosophila. Herein, we studied this model in the genus Anastrepha (Diptera, Tephritidae). Due to the remarkable advantages it presents, it is possible to cross species with different Adh genotypes and with different phenotype traits related to ethanol tolerance. The two species studied here each have a different number of Adh gene copies, whereby crosses generate polymorphisms in gene number and in composition of the genetic background. We measured certain traits related to ethanol metabolism and tolerance. ADH specific enzyme activity presented gene by environment interactions, and the larval protein content showed an additive pattern of inheritance, whilst ADH enzyme activity per larva presented a complex behavior that may be explained by epistatic effects. Regression models suggest that there are heritable factors acting on ethanol tolerance, which may be related to enzymatic activity of the ADHs and to larval mass, although a pronounced environmental effect on ethanol tolerance was also observed. By using these data, we speculated on the mechanisms of ethanol tolerance and its inheritance as well as of associated traits.     

Cytogenetic study of F1 hybrids betweenCrepis dinarica andCrepis froelichiana (Asteraceae)

Crepis dinarica andC. froelichiana are two closely related species of theC. praemorsa complex. Even though they exhibit the same chromosome number (2n = 8) and similar idiogram shape, they differ widely in quantity and distribution of heterochromatin bands. The hybrids between these two species comprise three morphological types. Parental genomes were distinguished in hybrids by Giemsa differential staining (C-banding). Although meiosis presents only a few abnormalities (about 2.4%), the percentage of aborted pollen grains is very high (90%).     

Transferability and characterization of microsatellite markers in two Neotropical Ficus species

Microsatellite markers were transferred and characterized for two Neotropical fig tree species, Ficus citrifolia and Ficus eximia. Our study demonstrated that microsatellite markers developed from different subgenera of Ficus can be transferred to related species. In the present case, 12 of the 15 primer pairs tested (80%) were successfully transferred to both of the above species. Eleven loci were polymorphic when tested across 60 F. citrifolia and 60 F. eximia individuals. For F. citrifolia, there were 4 to 15 alleles per locus, whereas expected heterozygosities ranged from 0.31 to 0.91. In the case of F. eximia, this was 2 to 12 alleles per locus and expected heterozygosities from 0.42 to 0.87.     

Cytogenetic analysis of three sea catfish species (Teleostei, Siluriformes, Ariidae) with the first report of Ag-NOR in this fish family

Despite their ecological and economical importance, fishes of the family Ariidae are still genetically and cytogenetically poorly studied. Among the 133 known species of ariids, only eight have been karyotyped. Cytogenetic analyses performed on Genidens barbus and Sciades herzbergii revealed that both species have 2n = 56 chromosomes and Cathorops aff. mapale has 2n = 52 chromosomes: Genidens barbus has 10 Metacentrics (M), 14 Submetacentrics (SM), 26 Subtelocentrics (ST), and 6 Acrocentrics (A), Sciades herzbergii has 14M, 20SM, 18ST and 4A, whereas Cathorops aff. mapale has 14M, 20SM, and 18ST. The nucleolus organizer regions (NORs) were found in a single chromosome pair on the short arm of a large-sized ST pair in Genidens barbus and on the short arm of a middle-size SM pair in Cathorops aff. mapale. Multiple NORs on the short arms of two large-sized ST pairs were found in Sciades herzbergii. The occurrence of diploid numbers ranging from 2n = 52 through 56 chromosomes and the presence of different karyotypic compositions, besides the number and position of NORs suggest that several numeric and structural chromosome rearrangements were fixed during the evolutionary history of this fish family.     

Genome size and base composition variation in natural and experimental Narcissus (Amaryllidaceae) hybrids

Background and Aims

Although there is evidence that both allopolyploid and homoploid hybridization lead to rapid genomic changes, much less is known about hybrids from parents with different basic numbers without further chromosome doubling. Two natural hybrids, Narcissus × alentejanus (2n = 19) and N. × perezlarae (2n = 29), originated by one progenitor (N. cavanillesii, 2n = 28) and two others (N. serotinus, 2n = 10 and N. miniatus, 2n = 30, respectively) allow us to study how DNA content and composition varies in such hybrids.

Methods

Flow cytometry measurements with two staining techniques, PI and DAPI, were used to estimate 2C values and base composition (AT/GC ratio) in 390 samples from 54 wild populations of the two natural hybrids and their parental species. In addition, 20 synthetic F₁ hybrid individuals were also studied for comparison.

Key Results

Natural hybrids presented 2C values intermediate between those found in their parental species, although intra-population variance was very high in both hybrids, particularly for PI. Genome size estimated from DAPI was higher in synthetic hybrids than in hybrids from natural populations. In addition, differences for PI 2C values were detected between synthetic reciprocal crosses, attributable to maternal effects, as well as between natural hybrids and those synthetic F₁ hybrids in which N. cavanillesii acted as a mother.

Conclusions

Our results suggest that natural hybrid populations are composed of a mixture of markedly different hybrid genotypes produced either by structural chromosome changes, consistent with classic cytogenetic studies in Narcissus, or by transposon-mediated events.     

Two new species of Pseudancistrus (Siluriformes,Loricariidae) from the Amazon basin,northern Brazil

Two new species of Pseudancistrus, a genus diagnosed by non-evertible cheek plates and hypertrophied odontodes along the snout margin, are described from two drainages of the Brazilian Shield: Pseudancistrus kayabi from the rio Teles Pires (rio Tapajós basin) and Pseudancistrus asurini from the rio Xingu. The new species are distinguished from congeners (Pseudancistrus barbatus, Pseudancistrus corantijniensis, Pseudancistrus depressus, Pseudancistrus nigrescens, Pseudancistrus reus, and Pseudancistrus zawadzkii) by the coloration pattern. Pseudancistrus kayabi has dark bars on the dorsal and caudal fins which are similar to that of Pseudancistrus reus from the Caroní River, Venezuela. Pseudancistrus asurini is unique among Pseudancistrus in having whitish tips of the dorsal and caudal fins in juveniles to medium-sized adults.     

The ultrastructure of Sorubim lima (Teleostei, Siluriformes, Pimelodidae) spermatogenesis: premeiotic and meiotic periods

The ultrastructure of Sorubim lima spermatogenesis during the premeiotic and meiotic periods was studied. Our observations showed that the germ cells in the cysts are connected by cytoplasmic bridges and the mitotic and meiotic divisions are slightly asynchronous. The first and the last spermatogonial generations differ in the cellular and nuclear volume, nucleolus, chromatin condensation, distribution, size, density, and shape of the mitochondria, presence of 'lamellae anulata', amount and dimension of the 'nuages', and movement of the centrioles. In addition to the nuclear prophase structures, the spermatocyte I shows changes in all other cellular organelles and elongated vesicles appear in the cytoplasm. The accentuated cytoplasmic density and thickened walled vesicles are morphological characteristics that differentiate spermatocytes II from the other germ cells in the cysts of Sorubim lima testis.     

Natural hybridization between an outcrossing and a selfingPhlox (Polemoniaceae): The maternal species of F1 hybrids

Natural F₁ hybrids between the outcrossingPhlox drummondii and the predominantly selfingP. cuspidata were examined to ascertain the proportion of hybrid individuals mothered by each species. Species-specific restriction fragment patterns (both nrDNA and cpDNA) were established as markers, and synthetic hybrids of known parentage were utilized to determine that the chloroplast genome is maternally inherited. Of 89 mature natural hybrids examined, approximately two thirds were mothered byP. drummondii, the outcrosser. That the outcrosser should mother most hybrids is expected since it is dependent upon incoming pollen for fertilization, and hybrids may result when heterospecific pollen is received. The fact that the highly selfingP. cuspidata mothered nearly one third of the hybrids is surprising, and may be related to both pre-zygotic and post-zygotic factors. Which species mothers hybrids has important implications for the potential for introgression as well as its direction.     

Description and biology of two new species of Neotropical Liriomyza Mik (Diptera,Agromyzidae), mining leaves of Bocconia (Papaveraceae)

Liriomyza mystica Boucher & Nishida, sp. n., and Liriomyza prompta Boucher & Nishida, sp. n. are described from Costa Rica. Both species were reared from leaves of Bocconia frutescens L. (Papaveraceae). The latter species was also reared from B. arborea S. Watson. Larvae of L. mystica mine primary veins of large, relatively old, mature leaves, and L. prompta mine blades of small to large, mature leaves. These represent the first record of agromyzids feeding on Bocconia. Biological information is also given and illustrated.     

E2F1 regulation of the human myo-inositol 1-phosphate synthase (ISYNA1) gene promoter

Human myo-inositol 1-phosphate synthase (IP synthase; E.C. 5.5.1.4), encoded by ISYNA1, catalyzes the de novo synthesis of inositol 1-phosphate from glucose 6-phosphate. It is a potential target for mood-stabilizing drugs such as lithium and valproate. But, very little is known about the regulation of human IP synthase. Here, we have characterized the minimal promoter of ISYNA1 and show that it is upregulated by E2F1. Upregulation occurs in a dose-dependent fashion and can be suppressed by ectopic expression of Rb. EMSA and antibody supershift analysis identified a functional E2F binding motif at -117. Complex formation at this site was competed by an excess of unlabeled Sp1 oligo consistent with the -117 E2F site overlapping an Sp1 motif. Because the -117 E2F motif is not a high-affinity binding site, we propose that the upregulation of ISYNA1 occurs through the cooperative interaction of several low-affinity E2F binding motifs present in the minimal promoter.     

Cytogenetic studies of the F1 hybrids of Capsicum annuum with C. chinense and C. baccatum

Summary Partially sterile interspecific hybrids were obtained between C. annuum var. cerasiformis and C. chinense var. mishme (H₁), and C. annuum var. cerasiformis and C. baccatum var. pendulum (H₂). Morphologically the F₁ hybrids were intermediate between the corresponding parents. Meiosis was irregular in the two F₁ hybrids. Cytological analysis of the two F₁ hybrids revealed that the genome of C. annuum differs from C. chinense by two translocations and some minor structural alterations and from C. baccatum by two translocations, a single inversion and some minor structural alterations. Isolation barriers such as hybrid inviability, weakness and hybrid breakdown in the H₁ hybrid and, inaddition, desynapsis in the H₂, were operative in these taxa. The differences between the present findings and those reported earlier on the two F₁hybrids were attributed to differences in the genetic architecture of the taxa employed in hybridization.     

The identity of the Neotropical stingless bee Frieseomelitta meadewaldoi (Cockerell, 1915) (Hymenoptera, Apidae)

A new study of a surviving syntype of Trigona meadewaldoi Cockerell, 1915, was undertaken and several widely employed names for Neotropical stingless bees recognized as junior synonyms. A lectotype is designated for Trigona meadewaldoi and the following new synonymies established: Tetragona francoi Moure, 1946, and Trigona (Frieseomelitta) freiremaiai Moure, 1963. These nomenclatural matters are here settled and the species thoroughly characterized in advance of a forthcoming phylogenetic consideration of the genus Frieseomelitta von Ihering, 1912.     

Generic placement of the Neotropical species of " Phragmatobia" (Erebidae, Arctiinae), with a remarkable matrivorous species from the Peruvian Andes

Phragmatobia Stephens is briefly reviewed and a diagnosis is provided. The South American species currently placed in Phragmatobia Stephens are revised to two new genera, Andesobia Schmidt and De Freina, gen. n., and Patagobia Schmidt and De Freina, gen. n. (subtribe Spilosomina). Both Andesobia and Patagobia exhibit adaptations to high altitude habitats, including micropterous females in Andesobia (Patagobia females are unknown) and diurnal flight of males. The adults, immature stages, and mating behaviour of Andesobia jelskii (Oberthür, 1881) are described. Males of Andesobia jelskii enter the female cocoon to mate, and the micropterous, flightless females remain in the cocoon following oviposition where newly hatched larvae feed initially on the female’s body.Four species are included in Andesobia, Andesobia jelskii comb. n. (= Paracles imitatrix Rothschild, 1922, syn. n.), Andesobia flavata (Hampson, 1901), comb. n., Andesobia boliviana (Gaede, 1923), comb. n. (=Turuptiana flavescens Rothschild, 1933, syn. n.), and Andesobia sanguinea (Hampson, 1907), comb. n. Patagobia includes only Patagobia thursbyi (Rothschild, 1910), comb. n., and Patagobia thursbyi pluto Toulgoët is relegated to its synonymy. Patagobia shows affinities to Phaos Walker, 1855 of Australia, Metacrias Meyrick, 1886 of New Zealand, and Pseudophragmatobia Krüger, 2009 of South Africa, suggesting a common ancestry of circumantarctic origin. Phragmatobia karsholti Toulgoët, 1991 is transferred to Venedictoffia Toulgoët, comb. n., an unrelated genus that is removed from subtribe Arctiina and provisionally placed in the Phaegopterina. Phragmatobia oberthueri Rothschild, 1910, described from Tibet, is a synonym of Lachana alpherakii (Grum-Grzhimailo, 1891) [Erebidae: Lymantriinae], syn. n., comb. n.     

The karyotype of three Brazilian Terrarana frogs (Amphibia, Anura) with evidence of a new Barycholos species

A recent substantial rearrangement of the 882 described eleutherodactyline frog species has considerably improved the understanding of their systematics. Nevertheless, many taxonomic aspects of the South American eleutherodactyline species remain unknown and require further investigation using morphological, cytogenetic and molecular approaches. In this work, the karyotypes of the Brazilian species Ischnocnema juipoca (Atibaia and Campos do Jordão, SP), Barycholos cf. ternetzi (Uberlândia, MG, and Porto Nacional, TO), and Pristimantis crepitans (Chapada dos Guimarães and São Vicente, MT) were analyzed using Giemsa staining, Ag-NOR labeling, and C-banding techniques. All individuals had a diploid number of 22 chromosomes, but the Fundamental Numbers were different among species. The herein described low chromosome number of Pristimantis crepitans is unique within this genus, suggesting that cytogenetically this species is not closely related either to its congeneric species or to Ischnocnema. In addition, karyotype differences, mainly in the NOR position, clearly distinguished the two Barycholos populations, besides indicating the existence of a so far undescribed species in this genus. A taxonomic review could clarify the systematic position of P. crepitans and verify the hypothetic new Barycholos species.     

An illustrated key to Neotropical species of the genus Meteorus Haliday (Hymenoptera,Braconidae, Euphorinae)

A comprehensive key for 75 species of Meteorus distributed across 15 Neotropical countries is presented. Eleven new species from Bolivia, Costa Rica and Ecuador are described: Meteorus albistigma, Meteorus carolae, Meteorus eurysaccavorus, Meteorus fallacavus, Meteorus flavistigma, Meteorus haimowitzi, Meteorus magnoculus, Meteorus martinezi, Meteorus microcavus, Meteorus noctuivorus and Meteorus orion. Expanded range distributions are recorded for Meteorus andreae, Meteorus farallonensis, Meteorus guineverae, Meteorus jerodi, Meteorus kraussi, Meteorus papiliovorus and Meteorus quimbayensis. The host of Meteorus jerodi is reported for the first time: a noctuid larva feeding on Asteraceae. Meteorus papiliovorus is recorded attacking Papilionidae larvae in Ecuador, therefore displaying a similar host family preference as formerly documented from Costa Rica and Colombia.