Synlophe patterns of the Haemonchinae of ruminants (Nematoda: Trichostrongyloidea)

The pattern of longitudinal ridges (synlophe) on the external cuticular surface of trichostrongylid nematodes has been shown to be of value for distinguishing species and determining relationships among higher taxa. In the process of studying Mecistocirrus digitatus, the large stomach worm of bovids of Asia that has been imported and established in the Americas, we observed remarkably similar synlophe patterns to those described for 3 species of Haemonchus and to those we examined in a species of Ashworthius. In all 3 genera, the synlophe is absent from the posterior part of the body. Only in Haemonchus does the synlophe extend beyond midbody. In both M. digitatus and Ashworthius sidemi, the synlophe extends posteriorly only about 1/4 of body length. In all 3 genera, the synlophe consists of about 30 ridges in the region of the esophagus with variation among species in specific areas, including additional pairs of subventral and subdorsal ridges and different lengths of sublateral ridges. This information is useful for identifying species and determining relationships among these large stomach worm parasites of cattle, sheep, goats, and farmed and wild cervids.     

A report of the first case of Dirofilaria infection in the eyelid region in Japan

Dirofilaria worms were recovered from a painless hard tumor in the right eyelid of a 19-year-old Japanese male who had lived in Kagoshima and Kumamoto Prefectures, Japan. In the worms, the cuticle had a smooth surface, the inner cuticular layer had internal lateral longitudinal ridges, and the musculature of the body wall was the polymyarian type. On the basis of all morphological characteristics observed, this worm was identified as an immature female Dirofilaria immitis. This is the first human case of nematode infection in the eyelid in Japan. Surgical removal of the mass with worms resulted in complete recovery from swelling of his right eyelid.     

中国黄耆属簇毛黄耆亚属的叶表皮特征及其系统学意义

在光学显微镜和扫描电镜下,观察了国产黄耆属簇毛黄耆亚属16种1变种的叶表皮特征。结果表明,气孔器在各种植物的上、下表皮均有分布,多为无规则型,也有不等细胞型;叶表皮细胞形状有不规则形与多边形,表皮细胞垂周壁有平直、浅波状、波状或深波状。叶表皮细胞形状与垂周壁的式样可以分为四种类型,这四种类型与亚属的分组有一定的对应关系。在扫描电镜下可见表皮细胞上有角质层,气孔下陷,气孔的外拱盖及其内缘特征在亚属内都比较一致。表皮细胞角质层的纹饰在个别类群中有一定的变异,对种类的鉴定有一定的意义。     

Scanning electron microscopy of the eggs of Ascaris lumbricoides, A. suum, Toxocara canis, and T. mystax.

Eggs of Ascaris lumbricoides, A. suum, Toxocara canis, and T. mystax were examined by scanning electron microscopy (SEM). All species under study exhibited pronounced surface ridges. The ridges formed distinctive patterns in T. canis and T. mystax. In the Ascaris species, the ridges are similar except that they are more pronounced in the eggs of A. suum. Operculumlike structures were observed only in Ascaris. Correlation of data from SEM with previously reported transmission electron microscopy suggests that the surface ridges seen in Ascaris eggs are formed by the chitinous layer of the shell.     

Dirofilaria cancrivori sp. n. (Nematoda: Filarioidea from the crabdog, Procyon cancrivorus, in Guyana

Dirofilaria cancrivori sp. n. is described from subcutaneous tissues of the crabdog, Procyon cancrivorus, in Guyana, South America. The filarid is morphologically distinct from Dirofilaria tenuis, parasite of a related host, the raccoon, in the southern United States, and all other species of Dirofilaria. The parasite can be distinguished from other dirofilarias based on a combination of morphological features including its size, number, and arrangement of caudal papillae on the male tail, size and shape of the spicules, the presence of longitudinal ridges and transverse striations on the cuticle, and the microfilaria.     

Influence of intercodon and base frequencies on codon usage in filarial parasites

Base frequency, codon usage, and intercodon identity were analyzed in five filarial parasite species representing five Onchocercidae genera. Wucheria bancrofti, Brugia malayi, Onchocerca volvulus, Acanthocheilonema viteae, and Dirofilaria immitis gene sequences were downloaded from NCBI, and analysis was performed using locally designed computer programs and other freely available applications. A clear sequence bias was observed among the nematode species examined. At the nucleotide level, AT basepairs were present in gene sequences at higher frequencies than GC. In addition, codons ending in A or T were used proportionately more than those with G or C in the third-codon position. In addition, the amino acids used most often corresponded to codons ending in AT basepairs. Intercodon base proportion was biased in that A was found most often at N4, second only to T in certain specific cases. Since all of these sequence biases were observed in a relatively consistent fashion among all of the organisms studied, we conclude that sequence bias is a genetic characteristic, which is associated with multiple filarial genera.     

苔草属复序苔草亚属植物果皮的扫描电镜观察

应用扫描电子显微镜 ,观察了 15种苔草属复序苔草亚属植物果皮的微形态特征。结果表明 ,复序苔草亚属植物果皮的微形态性状多种多样 ,可以为系统学研究提供较丰富的信息 ;并且在所观察的种类中 ,果皮的微形态特征在种内很稳定 ,种间存在不同程度的差异 ,某些近缘种也可表现出一定的相似性。因此 ,上述特征可以做为探讨种之间的分类及亲缘关系的参考。     

骨碎补科植物叶表皮特征及其系统学意义

基于骨碎补科(Davalliaceae)植物属的界定和属下等级的划分一直存在较大争议,本研究首次对骨碎补科6属39种(秦仁昌系统)植物的叶表皮进行了扫描电镜观察。结果显示,骨碎补科有9种类型的角质层,其中,阴石蕨属(Humata)的角质层有密集的孔状凹陷结构;Wibelia条纹突起较厚,排列整齐且细密紧致;广义钻毛蕨属(Davallodes)内存在多种角质层类型,需要在属下进一步细分。本研究还根据角质层特征讨论了骨碎补科与一些近缘种类的关系。角质层特征是骨碎补科内种属分类的重要依据,而保卫细胞形状和气孔密度,均不能用来界定骨碎补科的属和种。本研究按角质层分类的结果与Kato和Tsutsumi的分子系统学分类观点一致。     

Phylogenetic relationships among the subfamily Coregoninae as revealed by mitochondrial DNA restriction analysis

Mitochondria1 DNA (mtDNA) restriction analysis was used to assess phylogenetic patterns among 21 taxa of the subfamily Coregoninae. The genus Prosopium formed a very distinct group differing by 10% (sequence divergence estimate) from other species. Coregonus and Stenodus species were closely related, diverging by sequence divergence estimates of less than 5.6%. These species split into two major sister groups. One comprised all 'true whitefish' (subgenus Coregonus ) and four cisco species (subgenus Leucichrhys ). The most distant species within this assemblage was the Acadian whitefish ( C. huntsmani ). The other group included all other cisco species and also the Inconnu ( Stenodus leucichthys ). These results supported a polyphyletic origin of the ciscoes, and did not support Stenodus as a sister taxon of the genus Coregonus . The levels of sequence divergence observed suggested that most extant coregonines radiated during the Pleistocene.     

Morphological diversity of first instar larvae in Miltogramma subgenus Pediasiomyia (Diptera: Sarcophagidae, Miltogramminae)

The morphology of first instar larvae of three species of Miltogramma Meigen subgenus Pediasiomyia Rohdendorf is described using SEM and light microscope techniques. Miltogramma chrysochlamys (Rohdendorf), Miltogramma margiana (Rohdendorf) and Miltogramma przhevalskyi (Rohdendorf) share with other satellite flies the presence of an elongated sensillum basiconicum of the maxillary palpus and numerous longitudinal cuticular ridges on the integument of all segments; and they share with other Miltogramma spp. a maxillary palpus situated on a more or less raised base. While the first instar M. margiana is very similar to first instars of Miltogramma (sensu stricto), first instars of M. chrysochlamys and M. przhevalskyi share several features unique among Miltogramminae: antennal dome situated on a flat or indistinct basal ring, antennal dome flattened, border between pseudocephalon and first thoracic segment with a pair of fleshy processes, and basal ring with trichoid sensillum. First instars of M. chrysochlamys and M. przhevalskyi are unique in having both sb1 and sb2 of the sensilla basiconica of the maxillary palpus elongated, and M. przhevalskyi has an unpaired, median proleg on most abdominal segments.     

Rapid divergence of microsatellite abundance among species of Drosophila

Among major taxonomic groups, microsatellites exhibit considerable variation in composition and allele length, but they also show considerable conservation within many major groups. This variation may be explained by slow microsatellite evolution so that all species within a group have similar patterns of variation, or by taxon-specific mutational or selective constraints. Unfortunately, comparing microsatellites across species and studies can be problematic because of biases that may exist among different isolation and analysis protocols. We present microsatellite data from five Drosophila species in the Drosophila subgenus: D. arizonae, D. mojavensis, and D. pachea (three cactophilic species), and D. neotestacea and D. recens (two mycophagous species), all isolated at the same time using identical protocols. For each species, we compared the relative abundance of motifs, the distribution of repeat size, and the average number of repeats. Dimers were the most abundant microsatellites for each species. However, we found considerable variation in the relative abundance of motif size classes among species, even between sister taxa. Frequency differences among motifs within size classes for the three cactophilic species, but not the two mycophagous species, are consistent with other studied Drosophila. Frequency distributions of repeat number, as well as mean size, show significant differences among motif size classes but not across species. Sizes of microsatellites in these five species are consistent with D. virilis, another species in the subgenus Drosophila, but they have consistently higher means than in D. melanogaster, in the subgenus Sophophora. These results confirm that many aspects of microsatellite variation evolve quickly but also are subject to taxon-specific constraints. In addition, the nature of microsatellite evolution is dependent on temporal and taxonomic scales, and some variation is conserved across broad taxonomic levels despite relatively high rates of mutation for these loci.     

中国五味子属植物叶表皮研究

用浓硫酸－铬酸离析法,在光学显微镜下观察了中国五味子属植物１４种,１亚种,２变种,共２４个样品成熟叶的叶表皮细胞及气孔器特征,结果表明：五味子属植物叶片的上、下表皮细胞呈多边形或不规则形,垂周壁式样为平直,菜或浅汉浪;少数种类上表皮有气孔器或分泌细胞,所有的种类下表皮具气孔器和分泌细胞;气孔器类型以平列型为主,并伴有侧列型,极少数出现不规则型,气孔极区呈稍角质和厚或棒形角质加厚,稀Ｔ形角质加厚,叶     

Chromosomal localization of 5S and 18S rDNA in five species of subgenus Strobus and their implications for genome evolution of Pinus

BACKGROUND AND AIMS: Studying the genome structure of pines has been hindered by their large genomes and uniform karyotypes. Consequently our understanding of the genome organization and evolutionary changes in different groups of pines is extremely limited. However, techniques are now available that can surmount these difficulties. The purpose of this study was to exploit some of these techniques to characterize the genome differentiation between the two subgenera of Pinus: Pinus and Strobus. METHODS: Double-probe fluorescence in-situ hybridization (FISH) was used to localize the 5S and 18S rDNA loci on chromosomes of five species from the subgenus Strobus: P. bungeana, P. koraiensis, P. armandii, P. wallichiana and P. strobus. * KEY RESULTS: The rDNA FISH pattern varied considerably among the five species, with P. bungeana being the most distinct. By comparing the results obtained with those of previous rDNA FISH studies of members of the subgenus Pinus, several general features of rDNA loci distribution in the genus Pinus can be discerned: (a) species of subgenus Strobus generally have more rDNA loci than species of subgenus Pinus, correlating with their larger genomes in the subgenus Strobus; (b) there is a clear differentiation in 5S and 18S rDNA loci linkage patterns between the two subgenera; (c) variations in the rDNA FISH pattern correlate with phylogenetic relationships among species within the subgenus; (d) P. bungeana has fewer 18S rDNA sites than other pines investigated to date, but they give intense signals, and may reflect the primary distribution of the 18S-25S rDNA loci in the genus. CONCLUSIONS: The stable differentiation in rDNA FISH pattern between the subgenera suggests that chromosomal rearrangements played a role in the splitting of the two subgenera, and transpositional events rather than major structural changes are likely responsible for the variable rDNA distribution patterns among species of the same subgenus with conserved karyotypes.     

国产堇菜属植物花粉形态的研究

本文应用光学显微镜及扫描电镜对国产３２种堇菜属植物的花粉形态进行了观察,结果表明,在光学显微镜下,除Ｖ．ｔｒｉｃｏｌｏｒＬ．外,堇菜属植物的花粉形态比校一致,对本属的分类意义不大。在扫描电镜下的花粉外壁纹饰亦表明本属是一个较为自然的类群。但国产四亚属之间的花粉在外壁纹饰,颗粒的多少和有无,穿孔的多少和有无等方面存在着较明显的差异,而在亚属内则分化校小。支持了Ｊｕｚｅｐｃｈｕｋ（１９４９）和王庆瑞（１９９１）的分类处理。     

Application of epidermal morphology to taxonomic delimitations in the genus Jatropha L. (Euphorbiaceae)*

SEM examination of the epidermis of mature leaves of 37 species in the ten sections of Jatropha (Euphoi-biaceae) has provided information consistent with an earlier revision of the genuS. All species examined show basic paracyic stomata, excluding J.fremontioides which has anisocytic stomata. Subgenera are well demarcated by presence of true paracytic stomata in subgenus Curcas and hrachyparacytic stomata in subgenus Jatropha. The two subgenera can also be distinguished by the presence of smooth hairs in subgenusJatropha and verrucose hairs in subgenus Curcas (except in section Curcas).Uniseriate, inulticellular hairs occur only in the three most advanced.closely related.sections (Jatropha, Collenucia and Spinosae) in subgenus Jatropha.Similarities and dissimilarities of cuticular ornamentations, shape of the epidermal and vein cells and direction of anticlinal walls can be used as distinguishing characters, usually significant at the species level.     

Cuticle Micromorphology of Pinus krempfii Lecomte (Pinaceae) and Additional Species from Southeast Asia

Cuticle micromorphology of the unusual Vietnamese pine, Pinus krempfii Lecomte, and three additional endemic southeast Asian species of Pinus L. (Pinaceae) is characterized for the first time. Taxa studied include (1) P. krempfii, typically placed in its own subgenus Ducampopinus (Chevalier) Ferré ex Little & Critchfield; (2) the endemic Vietnamese species Pinus dalatensis Ferré and (3) the southeast Asian species Pinus kwantungensis Chun ex Tsiang, both of subgenus Strobus; and (4) the widespread Asian species Pinus kesiya Royle ex Gordon of subgenus Pinus. The current and previous studies demonstrate that the genus Pinus and its subgenera are delimited by unique combinations of cuticular characters, although some of these characters may occur individually in other conifers. Cuticular micromorphology supports taxonomic assignment of P. krempfii to subgenus Strobus rather than to its own subgenus, a result that is also indicated by other anatomical studies and recent molecular studies. Sectional affinities of P. krempfii are usually with Parrya, subsection Krempfianae. An alternative classification of P. krempfii with subsection Gerardianae can be supported by micromorphological characters including broad cuticular bridges between stomata, details of the intercellular flanges of the epidermal cells, and usually an amphistomatic stomatal distribution. Features of other Asian species studied are consistent with their taxonomic assignments. The study demonstrates the utility of cuticle micromorphology to taxonomic delimitation within the family Pinaceae.     

Vexillata liomyos n. sp. (Nemata: Ornithostrongylidae) from Liomys pictus (Rodentia: Heteromyidae) from Mexico, with comments on the synlophe of Vexillata armandae.

Individuals of a new species of Vexillata were collected from the small intestines of Liomys pictus from the Estaci6n de Biología Chamela, in Jalisco State, Mexico. The new species shows an array of characters that allow us to recognize it as a member of Vexillata; however, it can be distinguished from other species of the genus in that males possess an asymmetrical caudal bursa, females possess a characteristic cuticular inflation at the level of the ovijector, and both sexes possess a synlophe with 9 ridges at the midbody. Additional detail of the synlophe of Vexillata armandae Gardner et al., 1994 from Chaetodipus hispidus in New Mexico shows that both sexes have 12 cuticular ridges just posterior to the cephalic inflation, and in the posterior region of the body, females have 9 ridges of equal size while males possess 11 equal-sized ridges. In both sexes, the carene disappears at the posterior end of the body.     

A new Heligmonellid (Nematoda: Heligmonellidae) from Oecomys mamorae (Rodentia: Sigmodontinae) in the pantanal and new data on the synlophe of Guerrerostrongylus zetta from the Atlantic Forest, Brazil

A new species of Heligmonellidae nematode, Guerrerostrongylus gomesae n. sp., is described from specimens collected from the small intestine of the rodent Oecomys mamorae Thomas, 1906 in the Brazilian Pantanal. It differs from the 2 other species of the genus by the number of ridges in the synlophe 35-46 and 40-48 at the midbody in the male and female, respectively, by rays 8 arising at midlength of the dorsal trunk, ending near the margin of the caudal bursa, and the dorsal ray divided at the second-third part into 2 branches, each branch divided into 2 subequal subbranches. In addition, specimens of Guerrerostrongylus zetta Travassos, 1937 collected in Oligoryzomys nigripes Olfers, 1818 contain synlophe with 36-42 cuticular ridges in males and 38-42 in females at the midbody. By the characteristics of the synlophe and caudal bursa, Gerrerostrongylus gomesae n. sp. is considered a new species. We suggest that the number of cuticular ridges for this genus broadens the range of the cuticular ridges to at least 35 at midbody.     

Scanning electron microscopy of viable and calcified Onchocerca gibsoni

Holdsworth P. A. 1987. Scanning electron microscopy of viable and calcified Onchocerca gibsoni. International Journal for Parasitology17: 957–964. Scanning electron microscopy (SEM) of adult Onchocerca gibsoni revealed that the cephalic ends of male and female specimens possessed features of little value for differentiation from other species. The marked cuticular ridges of the mid-body region of female worms were highlighted using SEM, as were the cuticular annulations and the body constriction at the anal region. Male specimens revealed the uniform annulations of the worm body along with the caudal papillae and the spicules. Microfilariae (mff) possessed cephalic papillae, lateral lines and cuticular annulations similar to adult worms. The cephalic hook was the most prominent feature at the anterior end of the mff. Calcification of adult worms was found to be mainly internal, however, one specimen was recorded with external calcification. Energy dispersive X-ray analysis revealed the composition of the calcification to be of calcium phosphate.     

南五味子属花的形态及其系统学意义

借助扫描电镜观察了南五味子属(Kadsura)中黑老虎(K.coccinea)、南五味子(K.japonica)和狭叶南五味子(K.angustifolia)雄花和雌花的形态发生过程, 三种植物花发育早期相似而发育后期出现分异。根据花形态发生早期的相似性, 支持南五味子属为单系起源;根据花形态发生后期的分异状态, 支持将南五味子属分为离蕊南五味子亚属(Subgenus Cosbaea)和南五味子亚属(Subgenus Kadsura)。借助扫描电镜观察了短梗南五味子(K.borneensis)和披针叶南五味子(K.lanceolata)花的形态, 将南五味子和狭叶南五味子的花与短梗南五味子和披针叶南五味子的花比较, 赞成在南五味子亚属下设南五味子组(Section Kadsura)和南洋南五味子组(Section Sarcocarpon)。根据在狭叶南五味子中观察到的两性花痕迹和在五味子属(Schisandra)东亚五味子(S.elongata)花中观察到的两性花, 本文认为现存五味子科(Schisandraceae )植物的单性花可能由具两性花结构的祖先演化而来。根据五味子科植物柱头与八角科(Illiciaceae)植物柱头的相似性, 不支持将五味子科从八角目(Illiciales)中分出而成立五味子目(Schisandrales)的观点。