Longer or shorter spines: Reciprocal trait evolution in stickleback via triallelic regulatory changes in Stanniocalcin2a

Vertebrates have repeatedly modified skeletal structures to adapt to their environments. The threespine stickleback is an excellent system for studying skeletal modifications, as different wild populations have either increased or decreased the lengths of their prominent dorsal and pelvic spines in different freshwater environments. Here we identify a regulatory locus that has a major morphological effect on the length of stickleback dorsal and pelvic spines, which we term Maser (major spine enhancer). Maser maps in a closely linked supergene complex that controls multiple armor, feeding, and behavioral traits on chromosome IV. Natural alleles in Maser are differentiated between marine and freshwater sticklebacks; however, alleles found among freshwater populations are also differentiated, with distinct alleles found in short- and long-spined freshwater populations. The distinct freshwater alleles either increase or decrease expression of the bone growth inhibitor gene Stanniocalcin2a in developing spines, providing a simple genetic mechanism for either increasing or decreasing spine lengths in natural populations. Genomic surveys suggest many recurrently differentiated loci in sticklebacks are similarly specialized into three or more distinct alleles, providing multiple ancient standing variants in particular genes that may contribute to a range of phenotypes in different environments.

Growth temperature effect on mandibles' ontogeny and sexual dimorphism in the ambrosia beetle Xyleborus affinis (Curculionidae: Scolytinae)

Ambrosia beetles from the genus Xyleborus are important vectors of fungal pathogens in forest and agricultural systems, yet the influence of temperature on their morphological development has been poorly studied. Because host colonization and ambrosial fungi cultivation is mostly restricted to females, it is possible to speculate on strong sexual dimorphism expression in secondary sexual characters and ecological segregation between sexes. Here, we determined the effect of different growing temperatures (17, 23, 26 and 29 °C) on mandible ontogeny of larvae and adult individuals of X. affinis, and sexual dimorphism in adults, in shape and size variation using geometric morphometrics. Mandible shape change showed significant differences in magnitude and direction through larval ontogeny among temperature treatments. Sexual shape and size dimorphism were found in adult mandibles, and the degree of sexual dimorphism was dependent on growth temperature, with a significant effect of the interaction between temperature and sex on mandible shape and size variation. Higher morphological differences were observed at the base of mandibles among temperature treatments in adults and a gradual narrowing trend with temperature increments. These findings could have consequences on feeding performance and fungus cultivation inside colonies, potentially influencing their ability to establish populations in new geographical areas.

What about the males? the C. elegans sexually dimorphic nervous system and a CRISPR-based tool to study males in a hermaphroditic species

Sexual dimorphism is a device that supports genetic diversity while providing selective pressure against speciation. This phenomenon is at the core of sexually reproducing organisms. Caenorhabditis elegans provides a unique experimental system where males exist in a primarily hermaphroditic species. Early works of John Sulston, Robert Horvitz, and John White provided a complete map of the hermaphrodite nervous system, and recently the male nervous system was added. This addition completely realized the vision of C. elegans pioneer Sydney Brenner: a model organism with an entirely mapped nervous system. With this 'connectome' of information available, great strides have been made toward understanding concepts such as how a sex-shared nervous system (in hermaphrodites and males) can give rise to sex-specific functions, how neural plasticity plays a role in developing a dimorphic nervous system, and how a shared nervous system receives and processes external cues in a sexually-dimorphic manner to generate sex-specific behaviors. In C. elegans, the intricacies of male-mating behavior have been crucial for studying the function and circuitry of the male-specific nervous system and used as a model for studying human autosomal dominant polycystic kidney disease (ADPKD). With the emergence of CRISPR, a seemingly limitless tool for generating genomic mutations with pinpoint precision, the C. elegans model system will continue to be a useful instrument for pioneering research in the fields of behavior, reproductive biology, and neurogenetics.

Comparison of internal organs between myostatin mutant and wild-type piglets

BACKGROUND

Myostatin (MSTN) negatively regulates skeletal muscle development; however, its functions in internal organs have not been thoroughly investigated. Here, we compared the morphological, molecular, and biological characteristics of the heart, liver, spleen, lungs, kidneys, and tongue of homozygous MSTN mutant (MSTN^-/- ), heterozygous MSTN mutant (MSTN^+/- ), and wild-type (WT) piglets.

RESULTS

The heart and liver were lighter in MSTN^-/- piglets than in MSTN^+/- piglets, while the tongue was heavier in MSTN^-/- piglets than in WT piglets (P < 0.05). Furthermore, the tongue was longer in MSTN^-/- piglets than in WT piglets, and myofibers of the tongue were significantly larger in the former piglets than in the latter ones (P < 0.01). mRNA expression of MSTN in all organs was significantly lower in MSTN^-/- and MSTN^+/- piglets than in WT piglets (P < 0.05). Meanwhile, mRNA expression of follistatin, which is closely related to MSTN, in the heart and liver was significantly higher in MSTN^-/- piglets than in MSTN^+/- and WT piglets (P < 0.05). In addition, protein expression of MSTN in the heart, kidneys, and tongue was significantly lower in MSTN^-/- piglets than in WT piglets (P < 0.01).

CONCLUSION

These results suggest that MSTN is widely expressed and has marked effects in multiple internal organs. Myostatin has crucial functions in regulating internal organ size, especially the tongue. © 2019 Society of Chemical Industry.

Construction and Composition of the Squid Pen from Doryteuthis pealeii

The pen, or gladius, of the squid is an internalized shell. It serves as a site of attachment for important muscle groups and as a protective barrier for the visceral organs. The pen's durability and flexibility are derived from its unique composition of chitin and protein. We report the characterization of the structure, development, and composition of pens from Doryteuthis pealeii. The nanofibrils of the polysaccharide β-chitin are arranged in an aligned configuration in only specific regions of the pen. Chitin is secreted early in development, enabling us to characterize the changes in pen morphology prior to hatching. The chitin and proteins are assembled in the shell sac surrounded by fluid that has a significantly different ionic composition from squid plasma. Two groups of proteins are associated with the pen: those on its surface and those embedded within the pen. Only 20 proteins are identified as embedded within the pen. Embedded proteins are classified into six groups, including chitin associated, protease, protease inhibitors, intracellular, extracellular matrix, and those that are unknown. The pen proteins share many conserved domains with proteins from other chitinous structures. We conclude that the pen is one of the least complex, load-bearing, chitin-rich structures currently known and is amenable to further studies to elucidate natural construction mechanisms using chitin and protein.

Description of a new species of Surazomus (Arachnida: Schizomida), with comments on homology of male flagellum and mating march anchorage in the genus

Surazomus saturninoae sp. nov. is described from eastern Amazon. The male has a pentagonal flagellum, similar to those of three other species in the genus. These four species are herein gathered as the arboreus-group of Surazomus. We present a brief synopsis of chaetotaxy description in hubbardiines and several homology proposals for the flagellum of the species in the arboreus-group: the posterior lobes may be homologous to the lateral lobes of hubbardiine species with trilobed flagella; the setal brush with 4-5 setae on the posterior lobe may be composed of one Dl2 seta and enlarged lobular microsetae; the single, median posterior coupling pocket may be homologous to the pair of posterior pockets seen in other hubbardiines; the single, median anterior coupling pocket may be homologous to the pair of pockets on the anterior border of the flagellum seen in other hubbardiines. Based on the morphology of these pockets and the chelicerae within Surazomus, we discuss the anchoring mechanism during the mating march.

Rotation of sex combs in Drosophila melanogaster requires precise and coordinated spatio-temporal dynamics from forces generated by epithelial cells

The morphogenesis of sex combs (SCs), a male trait in many species of fruit flies, is an excellent system in which to study the cell biology, genetics and evolution of a trait. In Drosophila melanogaster, where the incipient SC rotates from horizontal to a vertical position, three signal comb properties have been documented: length, final angle and shape (linearity). During SC rotation, in which many cellular processes are occurring both spatially and temporally, it is difficult to distinguish which processes are crucial for which attributes of the comb. We have used a novel approach combining simulations and experiments to uncover the spatio-temporal dynamics underlying SC rotation. Our results indicate that 1) the final SC shape is primarily controlled by the inhomogeneity of initial cell size in cells close to the immature comb, 2) the final angle is primarily controlled by later cell expansion and 3) a temporal sequence of cell expansion mitigates the malformations generally associated with longer rotated SCs. Overall, our work has linked together the morphological diversity of SCs and the cellular dynamics behind such diversity, thus providing important insights on how evolution may affect SC development via the behaviours of surrounding epithelial cells.

The sex comb (SC) is a series of modified bristles on the male forelegs of many species of fruit flies. The size, position and shape of these sex combs vary drastically across different fly species. Therefore, SCs are a model system which illustrates the interaction between evolution and organism development influencing phenotypic features. In this work, we use a combined simulation-experimental approach to study the cellular processes involved in the rotation of developing SCs in common fruit flies (D. melanogaster). Our results indicate that despite the appearance of a complicated set of motions of surrounding cells associated with SC rotation, the final SC attributes only depend on a few selected parameters. We showed that changes in the timing and extent of cell size increase in distal cells altered the extent of SC rotation and breakage. Furthermore, these changes were sufficient to account for the observed variations in SC rotation between different fly species. Thus, our computational model has given us important insights on how evolution may use various cellular processes as a means to manifest the diversity of SCs across different fly species.

Developmental finite element analysis of cichlid pharyngeal jaws: Quantifying the generation of a key innovation

Advances in imaging and modeling facilitate the calculation of biomechanical forces in biological specimens. These factors play a significant role during ontogenetic development of cichlid pharyngeal jaws, a key innovation responsible for one of the most prolific species diversifications in recent times. MicroCT imaging of radiopaque-stained vertebrate embryos were used to accurately capture the spatial relationships of the pharyngeal jaw apparatus in two cichlid species (Haplochromis elegans and Amatitlania nigrofasciata) for the purpose of creating a time series of developmental stages using finite element models, which can be used to assess the effects of biomechanical forces present in a system at multiple points of its ontogeny. Changes in muscle vector orientations, bite forces, force on the neurocranium where cartilage originates, and stress on upper pharyngeal jaws are analyzed in a comparative context. In addition, microCT scanning revealed the presence of previously unreported cement glands in A. nigrofasciata. The data obtained provide an underrepresented dimension of information on physical forces present in developmental processes and assist in interpreting the role of developmental dynamics in evolution.

Exploration of Biological Markers of Feed Efficiency in Young Bulls

The efficiency with which ruminants convert feed to desirable products is difficult to measure under normal commercial settings. We explored the use of potential biological markers from easily obtainable samples, that is, blood, hair, and feces, to characterize potential causes of divergent efficiency when considered as residual feed intake (RFI) or feed conversion efficiency (FCE). A total of 54 Charolais bulls, 20 in period 1 and 34 in period 2, were examined for individual dry matter intake (DMI) and growth. Bulls were offered a diet of 70:30 wrapped grass silage to concentrate for 99 d. At the conclusion of the test period, blood samples were collected for the determination of vitamins B₂ and B₆, and plasma used for the determination of metabolites, natural isotopic ¹⁵N abundance (¹⁵N NIA, expressed as δ¹⁵N ‰) and fractionation (Δ¹⁵N_{plasma proteins-diet} and Δ¹³C_{plasma proteins-diet}) and near-infrared spectroscopy (NIRS). Feces were analyzed by NIRS. Bulls were slaughtered at 15-17 months of age and carcass characteristics determined. Bulls were ranked according to RFI with extremes (SD ± 0.5; n = 31) classified as either efficient (Neg-RFI) or inefficient (Pos-RFI). Extreme bulls were then classified for FCE (high vs low FCE), changing the groups. Pos-RFI bulls consumed 14% more feed than Neg-RFI bulls for the same level of weight gain. Low FCE bulls tended to eat more, but had lower weight gains than high FCE bulls. No differences were detected in carcass conformation, fat scores, hot carcass weight, or dressing percentage. Yet, heart and bladder weights were heavier in Pos-RFI, and rumen weight tended to be heavier in Pos-RFI bulls. RFI did not affect bulk ¹⁵N or ¹³C fractionation. A negative correlation was observed between FCE and Δ¹⁵N_{plasma proteins-diet}. Inefficient bulls (Pos-RFI) had higher δ¹⁵N in glycine compared to Neg-RFI bulls. Similarly, metabolomic analysis showed a tendency for concentrations of glycine and sarcosine to be elevated in Pos-RFI bulls, whereas aspartic acid and carnosine tended to be elevated, and serine tended to be lower in High FCE. Among vitamins, only flavin adenine dinucleotide concentration was higher in the blood of bulls with High FCE. These results suggest that the two feed efficiency metrics differ in the underlying mechanisms of metabolism, where RFI is driven by differences in the energetic requirements of visceral organs and the extent of AA catabolism.

Revision of the Oriental subfamily Heteropteryginae Kirby, 1896, with a re-arrangement of the family Heteropterygidae and the descriptions of five new species of Haaniella Kirby, 1904. (Phasmatodea: Areolatae: Heteropterygidae)

The areolate Oriental family Heteropterygidae Kirby, 1893 is critically reviewed and the results of the present study contradict the arrangement suggested by Zompro (2004), but in most aspects agree with a molecular study presented by Whiting et al (2003) and a phylogenetic study presented by Bradler (2009). The family is critically discussed and new hypotheses are presented for the phylogeny and intra-familiar relationships, placing the subfamily Dataminae Rehn & Rehn, 1939 as the basalmost clade of Heteropterygidae. The subfamilies Obriminae Brunner v. Wattenwyl, 1893 and Heteropteryginae Kirby, 1893 together represent the sister-group of Dataminae. Arguments and a tree are presented to support this hypothesis. New diagnoses and lists of genera are provided for all three subfamilies contained in Heteropterygidae, along with keys to distinguish between them.        The subfamily Obriminae is critically reviewed and the distinction between the three tribes Obrimini Brunner v. Wattenwyl, 1893, Eubulidini Zompro, 2004 and Miroceramiini Zompro, 2004 introduced by Zompro (2004) is shown to be poorly supported. While Obrimini sensu Zompro, 2004 is generally accepted (but now also contains genera that were placed in Eubulidini or Miroceramiini by Zompro (2004)), the tribes Eubulidini and Miroceramiini are not supported. A new arrangement is introduced, which is based on morphological characters neglected or overlooked by Zompro (2004) but were partly discussed by Bradler (2009). The genus Mearnsiana Rehn & Rehn, 1939 is removed from Miroceramiini and transferred to Obrimini. The genera Eubulides Stål, 1877, Heterocopus Redtenbacher, 1906, Theramenes Stål, 1875 and Stenobrimus Redtenbacher, 1906 are removed from Eubulidini and also transferred to Obrimini. Consequently, Eubulidini is synonymised with Obrimini (n. syn.). Miroceramiini is a monotypical tribe and only includes the Wallacean genus Miroceramia Günther, 1934. The new tribe Tisamenini n. trib. is established for the three basal genera Tisamenus Stål, 1875, Ilocano Rehn & Rehn, 1939 and Hoploclonia Stål, 1875 all of which were placed in Eubulidini by Zompro (2004). The latter genus differs from the other two genera by the morphology of the female genitalia, which is unique amongst the entire family. Three generic groups are recognized within Obrimini, the Obrimus-group, Stenobrimus-group and Theramenes-group. Keys are presented to distinguish between the three tribes now contained in the Obriminae, i.e. Obrimini, Tisamenini n. trib. and Miroceramiini. The genus Hennobrimus Conle, 2006 is synonymised with Mearnsiana Rehn & Rehn, 1939, based on the fact that the type-species of both genera are conspecific (n. syn.). Hennobrimus hennemanni Conle, 2006, the type-species of Hennobrimus, and Trachyaretaon manobo Lit & Eusebio, 2005 are synonymised with Mearnsiana bullosa Rehn & Rehn, 1939, the type-species of Mearnsiana (n. syn.). Theramenes dromedarius Stål, 1877 from the Philippines is removed from synonymy with the Wallacean Theramenes olivaceus (Westwood, 1859) and re-established as a valid species (rev. stat.).        The subfamily Heteropteryginae Kirby, 1896 is revised at the species-level and a new diagnosis is presented. Keys to the two genera and all 16 known species are provided along with new descriptions, differential diagnoses, lists of examined material, detailed information on the known distributions, measurements and illustrations of the insects and eggs. The intra-subfamiliar and intra-generic relationships are discussed and a cladogram is presented. Heteropteryginae contains two genera: Heteropteryx Gray, 1835 (Type-species: Phasma dilatatum Parkinson, 1798) and Haaniella Kirby, 1896 (Type-species: Phasma (Heteropteryx) muelleri de Haan, 1842). The distribution of this subfamily is restricted to Sundaland with the exception of a single species that is found in Vietnam. All other species are distributed in Borneo, Sumatra, the Mentawai Islands, Singapore, Peninsular Malaysia and Thailand. Heteropteryginae contains the largest and most striking members of the entire family Heteropteryginae, some of which are amongst the heaviest insects known. The subfamily is characterized by apomorphies such as the presence of wings, having a tympanal area (= stridulatory organ) in the basal portion of the alae, straight profemora, strongly shortened tarsi, lack of rough sensory-areas on the prosternum and typically X-shaped micropylar plate of the eggs. The sister-group of Heteropteryginae is represented by the Obriminae, with which it shares a beak-like secondary ovipositor in the females and presence of a medio-apical spine on the area apicalis. Both features are synapomorphies of Heteropteryginae + Obriminae.        The genus Haaniella Kirby, 1904 contains 16 known species, five of which are newly described herein. The genus Miniopteryx Zompro, 2004 (Type-species: Haaniella parva Günther, 1944) is synonymised with Haaniella on the basis that the distinguishing feature mentioned in the original description is a character that is frequently found throughout the genus (n. syn.). The type-species H. parva Günther, 1944 is automatically retransferred to Haaniella (rev. stat.). Haaniella aculeata n. sp. from western Sumatra is described from the male. Haaniella macroptera n. sp. from Singapore and the Johor state in southern Peninsular Malaysia is described from both sexes and the eggs. Haaniella gintingi n. sp. from Central Sumatra is described from both sexes and the eggs and Haaniella kerincia n. sp. from Western Sumatra is described from the insects only, the eggs being still unknown. One new species, Haaniella gorochovi n. sp., is the only representative of the genus and subfamily Heteropteryginae known from Vietnam and both sexes as well as the eggs are described. Haaniella erringtoniae (Redtenbacher, 1906) is endemic in Peninsular Malaysia, here removed from synonymy with H. muelleri (de Haan, 1842) and re-established as a valid species (rev. stat.). The Sumatran Haaniella glaber (Redtenbacher, 1906) is removed from synonymy with H. muelleri (Haan, 1842) and re-established as a valid species (rev. stat.). Leocrates glaber Redtenbacher, 1906 and Haaniella muelleri simplex Günther, 1944 are removed from synonymy with H. muelleri (Haan, 1842) (rev. stat.) and synonymised with H. glaber. Haaniella mecheli (Redtenbacher, 1906) and H. rosenbergii (Kaup, 1871) are removed from synonymy with H. muelleri (Haan, 1842) and re-established as valid species (rev. stat.). Haaniella erringtoniae novaeguineae Günther, 1934 and Haaniella muelleri var. b. (Haan, 1842) are synonymized with H. rosenbergii (Kaup, 1871) (n. syn.). The type-species Haaniella muelleri (Haan, 1842) is shown to be a fairly rare species that is restricted to Sumatra. All subsequent records of H. muelleri from outside Sumatra and references to captive breeding of stock originating from Peninsular Malaysia in Europe relate to H. erringtoniae (Redtenbacher, 1906). The previously unknown males and eggs of H. rosenbergii (Kaup, 1871) as well as the previously unknown females and eggs of H. parva Günther, 1944 are described and illustrated for the first time. Based on morphological characters of the insects and eggs three distinct species-groups are recognized within Haaniella. The muelleri species-group contains nine species that are distributed throughout Sumatra, the Mentawei Islands, Singapore and Peninsular Malaysia. These are characterized by the smooth ventral surface of the meso- and metafemora and lemon-shaped eggs which entirely lack the setae seen in the two other species-groups. The grayii species-group comprises four species, two of which are endemic in Borneo, one endemic in Sumatra and the fourth species being the only known representative of the subfamily in Vietnam. These species are characteristic for the prominent pair of spines on the abdominal tergites II-IV of males and long apically multidentate epiproct of females. The echinata species-group contains three exceptionally Bornean species, which are characterized by the long and apically pointed subgenital plate of females, which clearly projects beyond the epiproct, as well as the sub-basal lateral tooth of the anal segment of males. The muelleri species-group is sister to the remainder two species-groups.        Heteropteryx Gray, 1853 is a monotypical genus and only contains the type-species H. dilatata (Parkinson, 1798), which is found throughout Peninsular Malaysia, Thailand, Sumatra and Northeastern Borneo. This genus differs from Haaniella by the strongly conically elevated head, which posteriorly projects over the anterior margin of the pronotum, females being bright green or yellow in colour with plain and translucent pink alae and having distinct spines on the abdominal tergites, and males having a strongly shortened mesothorax and dull pink alae.        Lectotypes are designated for Haaniella parva Günther, 1944, Heteropteryx echinata Redtenbacher, 1906, Heteropteryx saussurei Redtenbacher, 1906 and Heteropteryx scabra Redtenbacher, 1906 to guarantee stability of these names.        Information on the habitats, host-plants, biology, life cycle, parasitism and captive breeding of the species of Heteropteryginae is presented and a list summarising all taxonomic changes presented herein.

Dynamic apical surface rings in superficial layer cells of koi Cyprinus carpio scale epidermis

This study examined the novel ring-shaped structures found in the apical surface of individual cells of the scale epidermis of koi Cyprinus carpio. These apical rings are highly dynamic structures with lifetimes ranging from a few to several minutes. While several ring forms were observed, the predominant ring morphology is circular or oval. Two distinct ring forms were identified and designated type I and type II. Type I rings have a well-defined outer border that encircles the surface microridges. Type II rings are smooth-surfaced, dinner-plate-like structures with membranous folds or compressed microridges in the centre. Type II rings appear less frequently than type I rings. Type I rings form spontaneously, arising from swollen or physically interrupted microridges but without initially perturbing the encircled microridges. After persisting for up to several minutes the ring closes in a centripetal movement to form a circular or irregular-shaped structure, the terminal disc. The terminal disc eventually disappears, leaving behind a submembranous vesicle-like structure, the terminal body. Type I rings can undergo multiple cycles of formation and closing. Recycling epidermal apical rings form through centrifugal expansion from the terminal disc followed by apparent contraction back to the disc structure, whereupon the cycle may repeat or cease. The findings demonstrate a novel skin surface structure in fishes and are discussed with respect to communication with the external aqueous environment.

A Note on Variations in Morphological Features of the Phlebotomine Sand Fly Sergentomyia bailyi (Diptera: Psychodidae) in a Population From Pondicherry UT, India

Morphological variations were observed in specimens of the sand fly species Sergentomyia bailyi Sinton 1931 collected from Pondicherry Union Territory, India. Examination of morphological characteristics showed differences in the length of sensilla chaeticum on antennal flagellomere 3 (A3) in males and females, in the size and shape of the spermathecae in females, and in the position of accessory spines on the gonostyle of males. In our previous study, DNA barcoding characterization of this sand fly species collected from Pondicherry UT revealed molecular variations within the S. bailyi population. This study confirms the existence of a species complex within S. bailyi population at Pondicherry UT.

Description of the Female of Martinsmyia minasensis (Diptera, Psychodidae, Phlebotominae), With Distribution Records and a Key to Female Identification

The adult female of the sand fly species Martinsmyia minasensis (Mangabeira, 1942) is described, and the characters of the genus Martinsmyia Galati, 1995 are defined. We performed morphometric analyses on the spermatheca and wings, and present data on the geographical distribution of M. minasensis, as well as an identification key to females of this genus. The specimens were measured, drawn, photographed, and compared with the similar species M. oliveirai. It was possible to distinguish between M. minasensis and M. oliveirai based on differences found in the common and individual ducts of the spermatheca, as well as wing shape and size.

A new species of tree crickets Oecanthus (Orthoptera, Gryllidae, Oecanthinae) in tobacco plantation from Southern Brazil, with body color variation

We provide herein a description of a new species of Oecanthus collected from the tobacco plantation in southern Brazil, municipality of São Lourenço do Sul, State of Rio Grande do Sul. Description focused metanotal gland features, phallic sclerites, and calling song. A large sampling of individuals was distributed into four groups according to body and appendages color and dotted. We also rank all kind of marks present in the scape and pedicel. We compare linear morphometric variables of the metanotal glands and tegmina, as well as calling song parameters between groups in order do define all of them as the same species. Photographs and measurements are provided.

Structural and Developmental Disparity in the Tentacles of the Moon Jellyfish Aurelia sp.1

Tentacles armed with stinging cells (cnidocytes) are a defining trait of the cnidarians, a phylum that includes sea anemones, corals, jellyfish, and hydras. While cnidarian tentacles are generally characterized as structures evolved for feeding and defense, significant variation exists between the tentacles of different species, and within the same species across different life stages and/or body regions. Such diversity suggests cryptic distinctions exist in tentacle function. In this paper, we use confocal and transmission electron microscopy to contrast the structure and development of tentacles in the moon jellyfish, Aurelia species 1. We show that polyp oral tentacles and medusa marginal tentacles display markedly different cellular and muscular architecture, as well as distinct patterns of cellular proliferation during growth. Many structural differences between these tentacle types may reflect biomechanical solutions to different feeding strategies, although further work would be required for a precise mechanistic understanding. However, differences in cell proliferation dynamics suggests that the two tentacle forms lack a conserved mechanism of development, challenging the textbook-notion that cnidarian tentacles can be homologized into a conserved bauplan.

Ghost shrimp Calliax de Saint Laurent, 1973 (Decapoda: Axiidea: Callianassidae) in the fossil record: systematics, palaeoecology and palaeobiogeography

Ghost shrimps of the family Callianassidae are very common in the fossil record, but mostly as isolated cheliped elements only. The assignment to biologically defined genera, diagnosed on the basis of soft part morphology, is thus rather difficult. In this respect, proxy characters present on chelipeds that are the most durable ghost shrimp remains are needed to ascribe fossil material to extant genera. The genus Calliax de Saint Laurent, 1973 has been particularly obscure in this respect. Thorough comparison of extant members of the genus resulted in evaluation of characters present on chelipeds being taxonomically important on the genus level, specifically: 1) rectangular major P1 propodus with two ridges on the base of the fixed finger extending onto manus; 2) major P1 fingers relatively short; and 3) minor P1 chela with dactylus longer than fixed finger and possessing a wide gap between fingers. On this basis, Callianassa michelottii A. Milne Edwards, 1860, from the Oligocene and Miocene of Europe is herein reassigned to Calliax. Further re-examination of the ghost shrimp fossil record revealed that C. szobensis Müller, 1984, from the Middle Miocene of Hungary represents the same animal as C. michelottii and they are synomymised herein. The known geographic distribution of C. michelottii is expanded by the first confirmed occurrence of the species in Slovakia. All occurrences of C. michelottii known to date are reviewed and documented. The presence of Calliax michelottii comb. nov. may be considered an indicator of deeper marine settings. Based on the scarce fossil record known to date, Calliax has a Tethyan origin; it supposedly migrated westward to establish present day communities in the Caribbean sometime before the Middle Miocene.

A new species of Diadema (Echinodermata: Echinoidea: Diadematidae) from the eastern Atlantic Ocean and a neotype designation of Diadema antillarum (Philippi, 1845)

Diadenia africanum sp. nov. Rodríguez et al. 2013 occurs in the eastern Atlantic Ocean at depths of 1-80 meters off Ma- deira Islands, Salvage Islands, Canary Islands, Cape Verde Islands, Sâo Tome Islands and at the continental coast off Sen- egal and Ghana. This species was previously considered an eastern Atlantic population of D. antillarum. Genetic distances between the holotype of D. africanum and the neotype of D. antillarun herein designated, measured 3.34% in Cytochrome oxidase I, 3.80% in ATPase-8 and 2.31% in ATPase-6. Such divergence is similar to that already highlighted between other accepted species of Diadena. Morphometric analysis of test, spine and pedicellarial characters also separated D. africanum from D. antillartn and reveals that this new species is morphologically similar to D. antillarum ascensionis from the mid Atlantic. The tridentate pedicellariae, which have been shown to have diagnostic characters which discriminate among species of Diadema, occur as both broad and narrow valved forms in D. antillarumn from the western Atlantic. In D. africanum the tridentate pedicellariae occur only as a single form which is characterized by moderately broad and curved valves, with an expanded distal gripping region. This form of tridentate pedicellaria is very similar to that of D. antillarum ascensionis from the central Atlantic, with only slight variations in valve serration and valve curvature differ- entiating the two forms.

Five new species of Baeus Haliday, 1833 (Hymenoptera: Platygastroidea: Scelioninae) from Brazil with an updated key to Neotropical species

The species of the genus Baeus are small endoparasitoids wasps that attack spiders' egg sacs. Although there are data of occurrence in several biogeographical regions, their distribution records are scarce, especially due to their small size, mak- ing difficult to collect them in natural environments. In this paper, five new species of Baeus are described as results of collections made in southeastern Brazil: Baeus fluminensis new species, B. itatiaiaensis new species, B. leucophthalmus new species, B. melanocephalus new species and B. morenus new species. An updated key to the known Neotropical spe- cies of the genus is also provided.

Species of the family Nemouridae (Plecoptera) from Taihang Mountains of northern China, with description of Nemoura taihangshana sp. n

A distinctive new species of the genus Nemoura is described from the Taihang Mountains of northern China, N. taihangshana. The new species is compared with similar species. Amphinemura sinensis (Wu, 1926) is redescribed and the first record of N. geei Wu, 1929 from Henan Province is also given.

A new species of the genus Mantisgebia Sakai, 2006 (Crustacea, Decapoda, Gebiidea, Upogebiidae) from the South China Sea

A new species of the genus Mantisgebia Sakai, 2006, M. multispinosa sp. nov., collected from the South China Sea, is described and illustrated. It is readily distinguished from the other three species of the genus by the numerous spines on the cervical groove, hepatic region, and lower margins of the antennular and antennal peduncles.

A remarkable new crab-like hermit crab (Decapoda: Paguridae) from French Polynesia, with comments on carcinization in the Anomura

Patagurus rex gen. et sp. nov., a deep-water pagurid hermit crab, is described and illustrated based on a single specimen dredged from 400 m off Moorea, Society Islands, French Polynesia. Patagurus is characterized by a subtriangular, vaulted, calcified carapace, with large, wing-like lateral processes, and is closely related to two other atypical pagurid genera, Porcellanopagurus Filhol, 1885 and Solitariopagurus Türkay, 1986. The broad, fully calcified carapace, calcified branchiostegites, as well as broad and rigidly articulated thoracic sternites make this remarkable animal one of the most crab-like hermit crabs. Patagurus rex carries small bivalve shells to protect its greatly reduced pleon. Carcinization pathways among asymmetrical hermit crabs and other anomurans are briefly reviewed and discussed.

New Neotropical species of Hygronemobius Hebard, 1913 (Orthoptera: Grylloidea: Nemobiinae), including a brief discussion of male genitalia morphology and preliminary biogeographic considerations of the genus

Three new Neotropical species of Hygronemobius Hebard are described from Atlantic Forest remnants in southeastern Brazil: Hygronemnobius indaia sp. n. and Hygroneinobius iperoigae sp. n. from the state of São Paulo and Hygroneinobius guriri sp. n. from the state of Espírito Santo. We provide photographs of types and male genitalia, and discuss the morphology of male genitalia, taxonomy, calling songs and biogeographic distribution of the genus.

Two new species of Psephenops Grouvelle from Belize (Coleoptera: Byrrhoidea: Psephenidae), with a key to the known species from Mexico and Central America

Two new species, Psephenops spiniparameri sp. nov. and P. shepardi sp. nov. are described, based on specimens collected from Cayo and Toledo Districts in Belize, bringing the total number of described species assigned to the genus to ten.

Prodasineura yulan (Odonata: Zygoptera: Platycnemididae), a new species from Sarawak

Prodasineura yulan is described from a male from Maludam National Park, Betong Division, Sarawak, Malaysian Borneo. It is allied to Prodasineura interrupta.

Larval morphology of dart-poison frogs (Anura: Dendrobatoidea: Aromobatidae and Dendrobatidae)

Tadpoles in the superfamily Dendrobatoidea (families Aromobatidae and Dendrobatidae), housed in zoological collections or illustrated in publications, were studied. For the most part, tadpoles of species within the family Aromobatidae, the subfamilies Colostethinae and Hyloxalinae (of the family Dendrobatidae), and those of the genus Phyllobates, Dendrobatinae (Dendrobatidae) have slender anterior jaw sheaths with a medial notch and slender lateral processes, triangular fleshy projections on the inner margin of the nostrils and digestive tube with constant diameter and color and its axis sinistrally directed, concealing the liver and other organs. These morphologies are different from the ones observed in tadpoles of species included in the Dendrobatinae (minus Phyllobates). Exceptions to these morphological arrangements are noted, being the digestive system arrangement and the nostril ornamentation more plastic than the shape of the upperjaw sheath. Tadpoles of all species of the Dendrobatoidea have similar disposition of digestive organs in early stages, but differentiate in late stages of development. Classifying the upper jaw sheath into the two recognized states is possible from very early stages of development, but gut disposition and nostril ornamentation cannot be determined until late in development, making classification and taxonomic assignment of tadpoles based on these morphological features challenging.

A new species of lowland karst dwelling Cnemaspis Strauch 1887 (Squamata: Gekkonidae) from northwestern Peninsular Malaysia

A new species of lowland karst dwelling Cnemaspis Strauch 1887, C. grismeri sp. nov. is described from the southeastern base of the Banjaran Bintang in northern Peninsular Malaysia. It is differentiated from its congeners by a unique combination of characters including size, coloration and scalation. Cnemapis grismeri sp. nov. is most closely related to C. mcguirei, an upland species endemic to the Banjaran Bintang. This phylogeographic pattern is also seen in the upland and lowland Banjaran Bintang species of Cyrtodactylus bintangtinggi and C. bintangrendah, respectively (Grismer et al. 2012). The discovery of yet another endemic gekkonid in the poorly explored karst regions of Peninsular Malaysia underscores the necessity for concentrated collecting efforts in these unique landscapes.

A revision of the genus Baeocera in Japan, with a new genus of the tribe Scaphisomatini (Coleoptera, Staphylinidae, Scaphidiinae)

The Japanese species of the genus Baeocera Erichson, 1845 are reviewed and a new genus Baeoceroxidium is established for Baeocera micros (Achard, 1923) and members of the Baeocera pilifera species group. The female genitalia are used for the first time in Baeocera for both, as species specific characteristics and to indicate relationships. Amaloceroschema Löbl, 1967 is placed in synonymy with Baeocera.

New occurrences of lithodid crabs (Crustacea: Decapoda: Lithodidae) from the coasts of Africa, with the description of a new species of Paralomis White, 1856

The Collection of Decapod and Stomatopod Crustaceans from the Cádiz Oceanographic Centre (CCDE-IEOCD) comprises a number of lithodid crabs from Spanish surveys carried out in African waters. The revision of this material allowed the confirmation of new records of Lithodesferox Filhol, 1885 in Guinea-Bissau and Mauritania, Lithodes mamillifer Macpherson, 1988 in Mozambique, Neolithodes asperrimus Barnard, 1947, Neolithodes grimaldii (A. Milne Edwards & Bouvier, 1894) and Paralomis erinacea Macpherson, 1988 in Mauritania, Paralomis africana Macpherson, 1982 in Namibia and Paralomis cristulata Macpherson, 1988 in Guinea-Bissau. Some of these records contribute to extent the geographical and/or bathymetrical range of the species. One new species of the genus Paralomis from Namibia is described and illustrated. This species shows close affinity with its congener Paralomis pectinata Macpherson, 1988, from Venezuela. The morphological differences between the two species are included.

A long-lost relic from the Eastern Ghats: Morphology, distribution and habitat of Sepsophis punctatus Beddome, 1870 (Squamata: Scincidae)

Sepsophis punctatus Beddome 1870, the only species of a monotypic genus, was described based on a single specimen from the Eastern Ghats of India. We rediscovered the species based on specimens from Odisha and Andhra Pradesh state, India, after a gap of 137 years, including four specimens from close to the type locality. The holotype was studied in detail, and we present additional morphological characters of the species with details on natural history, habitat and diet. The morphological characters of the holotype along with two additional specimens collected by Beddome are compared with the specimens collected by us. We also briefly discuss the distribution of other members of the subfamily Scincinae and their evolutionary affinities.

Sarcophaga (Hoa)flexuosa Ho (Diptera: Sarcophagidae): association of sexes using morphological and molecular approaches, and a redefinition of Hoa Rohdendorf

Sarcophaga flexuosa Ho, 1934 is the type species of the currently monotypic genus-group taxon Hoa Rohdendorf, 1937, which here is considered a subgenus of Sarcophaga Meigen, 1826. Using DNA sequences of mitochondrial genes (cytochrome oxidase I and cytochrome b), we positively identify, for the first time, the female of S. (H.)flexuosa. The female is described, the male is redescribed, and both sexes are illustrated using a combination of line drawings, photographs and scanning electron microscopy images. It is argued from the morphology of the male terminalia that Sarcophagaflexuosa is the sister taxon of Sarcophaga basiseta Baranov, 1931, and the subgenus Hoa is redefined to include both of these species.

A morphology-based phylogeny of the Liolaemus alticolor-bibronii group (Iguania: Liolaemidae)

The genus Liolaemus was split in two subgenera, Liolaenus sensu stricto and Eulaemus. Inside the Liolaemus sensu stricto subgenus, many groups have been proposed. One of them is the L. alticolor-bibronii group. Here, I studied 184 morpho- logical characters of more than one thousand specimens that of the L. alticolor-bibronii group. Many of these characters are original from this study, especially the characters related to color pattern. Also, I include eight population without tax- onomic status. Using those characters and terminal taxa, I performed phylogenetic analyses using parsimony as optimality criterion, under implied weight. Two different topologies were found. The results show that the L. alticolor-bibronii group is monophyletic, and that it is sister to the L. gravenhorsti group. This finding is congruent with previous morphological and molecular phylogenies. Also, nested within the L. alticolor-bibronii group the L. lemniscatus and the L. robertmen- tensi groups are found. In contrast to previous hypotheses, Liolaemus tacnae is never recovered as a member of the L. alticolor-bibronii group.

A new species of Bachia Gray, 1845 (Squamata: Gymnophthalmidae) from the western Brazilian Amazonia

A new species of Bachia of the B. dorbignyi group, Bachia scaea sp. nov., is described from the left bank of the upper Madeira River, at Rondônia state, at the western Brazilian Amazonia. The new species resembles morphologically B. dorbignyi and B. peruana, and seems to be related with the former species based on molecular data (16S and c-mos sequences). Nonetheless the presence of a first temporal separating parietal and supralabial scales and the absence of clawed fingers in the new species, can promptly distinguish it from their close relatives. This description ends with several-decades of stasis in the taxonomy of the Bachia dorbignyi group from Amazonian lowlands, and also presents new evidence that supports the Madeira River as a vicariant barrier.

New species and taxonomic rearrangements of Anostostomatid Crickets (Orthoptera: Stenopelmatoidea: Anostostomatidae) from the Neotropics

This paper describes and illustrates a new species of the genus Anabropsis (Anostostomatidae: Anabropsinae) from Colombia, we group the species of this genus were grouped into three groups: Mexicana, Alata and Aptera. A brief review of the genus Apotetainenus (Anostostomatidae: Lutosinae) is also given including a new species from the Colombian rainforest; also A. clipeatus is redescribed and a new distribution data are provided. Finally A. politus (Brunner, 1915) is designated as synonym of A. clipeatus.

A new species of Halaphanolaimus (Nematoda: Leptolaimidae) from the southern Black Sea (Turkey) with a modified key for species identification

Halaphanolaimus sergeevae n. sp. is described and illustrated from the Sinop coasts (southern Black Sea, Turkey). The new species morphologically resembles H. pellucidus Southern, 1914, but differs from it by having a higher number of tubular supplements (12-14 vs. 6-7), longer spicules (68-70 im vs 47-52 [tm), smaller tail/spicule ratio (1.6 vs. 2.7), smaller body size (926-1273 vs. 1500 microm), and smaller De Man indices of a, b and c'. An updated identification key to the species of Halaphanolainius is proposed.

Studies on the genus Aporcelaimellus Heyns, 1965 (Nematoda, Dorylaimida, Aporcelaimidae). Four atypical species with simple uterus from Southern Iberian Peninsula

Three new and one known species of the genus Aporcelaimellus, collected mainly in natural areas from the Iberian Peninsula and characterized by having a simple uterus and atypical caudal region are described and illustrated, including line drawings, LM pictures and/or SEM pictures. Aporcelaimellus deserticola sp. n. is distinguished by its body 1.79-2.43 mm long, lip region 14-16 pm broad and offset by expansion rather than by constriction, odontostyle 18-21 µm long, neck 464-555 µm long, pharyngeal expansion 234-283 µm long or 49-52% of total neck length, a dorsal cell mass present at level of anterior end of intestine, uterus 34-67 µm long or 0.6-1.1 times the corresponding body diameter, V= 49-55, tail conical with rounded terminus (29-43 µm, c = 47-66, c' = 0.9-1.4) and bearing a short but perceptible hyaline portion, and male unknown. Aporcelaimellus hyalinus sp. n. is characterized by its body 1.49-2.23 mm long, lip region offset by constriction and 13-16 µm broad, odontostyle 14-16 µm long, neck 389-474 µm long, pharyngeal expansion 183-242 µm long or 45-53% of total neck length, uterus 44-106 µm long or 0.7-1.8 times the corresponding body diameter, V = 48-55, tail conical with rounded terminus (27-41 µm, c = 38-68, c' = 1.0-1.4) and short inner core, spicules 56 µm long, and seven irregularly spaced ventromedian supplements. Aporcelaimellus rarus sp. n. is distinguished by its body 1.96-2.34 mm long, lip region offset by constriction and 14-16 µm broad, odontostyle 15-16 µm long, neck 411-518 µm long, pharyngeal expansion 196-270 µm long or 48-52% of total neck length, a dorsal cellular mass at a short distance behind the cardia, uterus 63-96 µm long or 0.8-1.5 times the corresponding body diameter, V= 51-56, female tail short and conical (28-40 µm, c = 50-74, c' = 0.7-0.9) with rounded terminus and bearing a dorsal concavity at its posterior half, and males unknown. New data are provided for A. salicinus. A discussion of these atypical species is also provided.

Taxonomic review of the Sebastes pachycephalus complex (Scorpaeniformes: Scorpaenidae)

A taxonomic review of the Sebastes pachycephalus complex established the existence of two valid species, S. pachycephalus and S. nudus. Similarities between them include: cranium armed dorsally with robust preocular, supraocular, postocular, and parietal spines; interorbital space concave; lower jaw lacking scales, shorter than upper jaw; thickened rays in ventral half of pectoral fin; dorsal fin usually with 13 spines and 12 soft-rays; pored lateral line scales 27-35 (usually 29-33). However, S. pachycephalus is distinguishable from the latter in having minute scales below the entire dorsal-fin spine base (vs. lacking minute scales below first to fifth or variously to the posteriormost spine in the latter), dark spots scattered on the dorsal, anal and caudal fins (vs. no distinct dark spots), and lacking distinct colored markings on the dorsum (vs. yellow or reddish-brown markings present). Although both species occur off the southern Korean Peninsula and in the Bohai and Yellow Seas, in Japanese waters, the former is distributed from northern Honshu Is. southward to southern Kyushu Is., whereas the latter extends from southern Hokkaido southward along the Pacific coast of Japan to Kanagawa, and along the Sea of Japan coast to northern Kyushu Is., including the Seto Inland Sea. Sebastes nigricaus, S. nigricans, and S. latus are confirmed as junior synonyms of S. pachycephalus, and S. chalcogrammus as junior synonym of S. nudus, based on the examination of type specimens.

New species of mouse spiders (Araneae: Mygalomorphae: Actinopodidae: Missulena) from the Pilbara region, Western Australia

Two new species of Mouse Spiders, genus Missulena, from the Pilbara region in Western Australia are described based on morphological features of males. Missulena faulderi sp. nov. and Missulena langlandsi sp. nov. are currently known from a small area in the southern Pilbara only. Mitochondrial cytochrome c oxidase subunit I (COI) sequence divergence failed in clearly delimiting species in Missulena, but provided a useful, independent line of evidence for taxonomic work in addition to morphology.

Two new species of Squalius, S. adanaensis and S. seyhanensis (Teleostei: Cyprinidae), from the Seyhan River in Turkey

Two new species of Squalius are described from the Seyhan River drainage in Turkey: S. adanaensis from the lower part of the drainage and S. seyhanensis from the upper part. Squalius adanaensis is distinguished from the other species of the genus in Anatolia, among other characters, by having the flank scales with a dark spot on each scale pocket but covered by the posterior margin of the previous scale, and very few melanophores along the posterior margin; 38-42 + 1-2 lateral line scales; and a maximum known size of 157 mm SL. Squalius seyhanensis is distinguished from other species of the genus in Anatolia, among other characters, by having the flank scales with a dark spot on each scale pocket, exposed, and densely-set melanophores along the posterior margin, forming a conspicuous reticulate pattern; 42-44 + 1-2 lateral line scales; and a maximum know size of 240 mm SL.

Revision of subgenera of Stenichnus Thomson, with review of Australo-Pacific species (Coleoptera, Staphylinidae, Scydmaeninae)

Subgenera of the speciose ant-like stone beetle genus Stenichnus Thomson are revised. The genus is re-classified and only two subgenera are retained: Stenichnus s. str. and Scydmaenichnus Reitter. Two remaining subgenera, Austrostenichnus Franz and Scydmaenilla King, are elevated to the genus rank (the status of Scydmaenilla, originally described as a genus and later reduced to a subgenus of Stenichnus, is restored). Two species occurring in New Zealand, Stenichnus insignis (Broun) and Stenichnus kuschelianus Franz, previously classified in Stenichnus (Austrostenichnus), are placed in a separate genus Zeanichnus gen. nov. (with Scydmaenus insignis Broun as a type species). Scydmaenilla is divided into two subgenera: Scydmaenilla s. str. and Scydmaenillunia subg. nov. (with Scydmaenilla adelaidensis Franz as a type species). Lectotypes are designated for Stenichnus (Scydmaenichnus) fossifrons Reitter, Scydmaenilla pusilla King and Scydmaenilla constricta Lea. All Australo-Pacific species, previously placed in Stenichnus, are redescribed: Austrostenichnus caledonicus Franz (New Caledonia), Zeanichnus insignis (Broun) comb. nov. (New Zealand), Zeanichnus kuschelianus (Franz) comb. nov. (New Zealand), Scydmaenilla (s. str.) pusilla King, stat. rest. (Australia), S. (s. str.) constricta Lea, stat. rest. (Tasmania), S. (s. str.) queenslandica Franz (Australia), S. (s. str.) thompsoniana Franz (Australia), S. (s. str.) brisbanensis Franz (Australia), S. (s. str.) sydneyana Franz (Australia), and S. (Scydmaenillunia) adelaidensis Franz (Australia). A possible synonymy of Scydmaenilla queenslandica and S. thompsoniana is discussed, not possible to verify on the basis of the available material.

A new species of Leptolalax (Anura: Megophryidae) from Gunung Mulu National Park, Sarawak, East Malaysia (Borneo)

We describe a new species of Leptolalax from Gunung Mulu National Park in eastern Sarawak, Malaysian Borneo. The new species had been assigned to Leptolalax dringi and Leptolalax gracilis in the past. It is shown to differ from both these species and from all other species of the genus by a unique combination of morphological characters including large body size, rounded snout, interorbital distance being smaller than width of upper eyelid, bipartite subgular vocal sac in males, basal toe webbing, shagreened skin with tiny tubercles on dorsum and dorsal side of head, angled supratympanic fold, small pectoral glands, absence of supraaxillary glands and ventrolateral glandular ridges, spotted venter, advertisement call consisting of long series of 8-289 notes, each composed of three or four pulses, and dominant frequency at 7225-9190 Hz, with prominent frequency modulation.

DNA replication events during larval silk gland development in the silkworm, Bombyx mori

The silk gland is an important organ in silkworm as it synthesizes silk proteins and is critical to spinning. The genomic DNA content of silk gland cells dramatically increases 200-400 thousand times for the larval life span through the process of endomitosis. Using in vitro culture, DNA synthesis was measured using BrdU labeling during the larval molt and intermolt periods. We found that the cell cycle of endomitosis was activated during the intermolt and was inhibited during the molt phase. The anterior silk gland, middle silk gland, and posterior silk gland cells asynchronously exit the endomitotic cycle after day 6 in 5th instar larvae, which correlated with the reduced expression of the cell cycle-related cdt1, pcna, cyclin E, cdk2 and cdk1 mRNAs in the wandering phase. Additional starvation had no effect on the initiation of silk gland DNA synthesis of the freshly ecdysed larvae.

Dynamics of endoreplication during Drosophila posterior scutellar macrochaete development

Endoreplication is a variant type of DNA replication, consisting only of alternating G1 and S phases. Many types of Drosophila tissues undergo endoreplication. However, the timing and the extent to which a single endocycling macrochaete undergoes temporally programmed endoreplication during development are unclear. Here, we focused on the dynamics of endoreplication during posterior scutellar (pSC) macrochaete development. Quantitative analyses of C values in shaft cells and socket cells revealed a gradual rise from 8C and 4C at 8 hours after pupal formation (APF) to 72C and 24C at 29 hours APF, respectively. The validity of the values was further confirmed by the measurement of DNA content with a confocal laser microscope. BrdU incorporation assays demonstrated that shaft cells undergo four rounds of endoreplication from 18 to 29.5 hours APF. In contrast, socket cells undergo two rounds of endoreplication during the same period. Statistical analyses showed that the theoretical C values, based on BrdU assays, nearly coincide with the actually measured C values in socket cells, but not in shaft cells after 22 hours APF. These analyses suggest that socket cells undergo two rounds of endoreplication. However, the mechanism of endoreplication in the shaft cells may change from 22 hours APF, suggesting the possibility that shaft cells undergo two or four rounds of endoreplication during the periods. We also found that the timing of endoreplication differs, depending on the type of macrochaete. Moreover, endocycling in shaft cells of both the left and right sides of pSC bristle lineages occurs in the same pattern, indicating that the process is synchronized for specific types of macrochaete. Our findings suggest that endocycling in macrochaete cell lineages can be a model for understanding mechanisms of endoreplication at the single-cell level.

Helicospiral growth in the whip black coral Cirrhipathes sp. (Antipatharia, Antipathidae)

The coiling pattern of the whip black coral Cirrhipathes sp. (Antipatharia, Antipathidae) was studied in four sites of the Bunaken Marine Park (North Sulawesi, Indonesia) characterized by different hydrodynamic conditions. The colonies show a helicospiral growth, with the polyps irregularly arranged on the external convex side of the turns of the stem. Only the colonies living in a very slow current environment reach the greatest lengths (up to 5 m) and show the highest number of rotations (up to 10, 3600°). The turns shape changes along the stem of the colonies, from the base to the apex, as evidenced by the ratio between the pitch and the diameter of each coil. In particular, the turns close to the basal plate have a smaller diameter and a larger pitch, while in the most distal turns, the diameter increases and the pitch decreases concurrently. We hypothesize that the shape variation of the whorls is triggered by the relationship between the growing stem and the intensity of the prevailing current. In this way, the colony can initially grow fast, moving away from the bottom, and then extend into the current, maximizing the plankton capture.

Morphogenesis of Drosophila melanogaster macrochaetes: cell fate determination for bristle organ

Formation of specialized spatial structures comprising various cell types is most important in the ontogenesis of multicellular organisms. An example is the D. melanogaster bristle organs. Bristles (micro- and macrochaetes) are external sensory organs, elements of the peripheral nervous system, playing the role of mechanoreceptors. Their comparatively simple organization comprising only four specialized cells and a common origin of these cells make macrochaetes a convenient model for studying cell differentiation. The four cells forming bristle organ result from two successive divisions of a single cell, sensory organ precursor (SOP) cell. The number of macrochaetes on drosophila body corresponds to the number of SOP cells. The morphogenesis of macrochaetes comprises three stages, the first two determining a neural fate of the cells. The third stage is cell specialization into components of the bristle organ-neuron, thecogen, tormogen, and trichogen. Development of each bristle commences from segregation of proneural clusters, of 20-30 cells, from the massif of undifferentiated cells of the wing imaginal disc. At this stage, each cluster cell can potentially become a SOP cell. At the second stage, the only SOP cell and its position are determined within each cluster. Finally, two asymmetric divisions of the SOP cell with subsequent differentiation of the daughter cells gives the bristle organ. Several dozens genes are involved in the control of macrochaete morphogenesis. The main component of this system is the proneural genes of achaete-scute complex (AS-C). An increased content of proneural proteins fundamentally distinguished the cells that will follow the neural developmental pathway from the disc epidermal cells. A local AS-C expression, initiated at specified disc sites by specific transcription factors, determines the number and topology of proneural clusters. The expression of AS-C genes, continuing in the cells of the cluster, increases the difference in proneural protein content, first, between the cluster cells and then, between the cluster cells and the single SOP cell, where it reaches the maximum level. This process is provided by both the intracellular regulation of AS-C gene activity and intercellular events mediated via the EGFR and Notch signaling pathways. The third stage in macrochaete morphogenesis comprises two successive asymmetric SOP cell divisions, determining the final specialization. The selector genes, in particular, numb, neuralized, tramtrack, and musashi, play the key role in cell type specification. This review systematizes the data on molecular genetic system controlling drosophila bristle morphogenesis and proposes an integral scheme of its functioning.

In vivo imaging of basement membrane movement: ECM patterning shapes Hydra polyps

Growth and morphogenesis during embryonic development, asexual reproduction and regeneration require extensive remodeling of the extracellular matrix (ECM). We used the simple metazoan Hydra to examine the fate of ECM during tissue morphogenesis and asexual budding. In growing Hydra, epithelial cells constantly move towards the extremities of the animal and into outgrowing buds. It is not known, whether these tissue movements involve epithelial migration relative to the underlying matrix or whether cells and ECM are displaced as a composite structure. Furthermore, it is unclear, how the ECM is remodeled to adapt to the shape of developing buds and tentacles. To address these questions, we used a new in vivo labeling technique for Hydra collagen-1 and laminin, and tracked the fate of ECM in all body regions of the animal. Our results reveal that Hydra 'tissue movements' are largely displacements of epithelial cells together with associated ECM. By contrast, during the evagination of buds and tentacles, extensive movement of epithelial cells relative to the matrix is observed, together with local ECM remodeling. These findings provide new insights into the nature of growth and morphogenesis in epithelial tissues.

Effects of 17β-estradiol and bisphenol A on the formation of reproductive organs in planarians

Planarians have a remarkable capacity for regeneration after ablation, and they reproduce asexually by fission. However, some planarians can also reproduce and maintain their sexual organs. During the regenerative process, their existing sexual organs degenerate and new ones develop. However, little is known about hormonal regulation during the development of reproductive organs in planarians. In this study, we investigated the effects of 17β-estradiol (a steroid) and bisphenol A (an endocrine disrupter) on the formation of sexual organs in the hermaphroditic planarian Dugesia ryukyuensis. Under control conditions, all worm tissues regenerated into sexual planarians with sexual organs within 4 weeks after ablation. However, in the presence of bisphenol A or 17β-estradiol, although they apparently regenerated into sexual planarians, the yolk glands, which are one of the female sexual organs, failed to regenerate even 7 weeks after ablation. These data suggest that planarians have a steroid hormone system, which plays a key role in the formation and maturation of sexual organs.

Regeneration of excised mantle tissue by the silver-lip pearl oyster, Pinctada maxima (Jameson)

This study investigated the capacity for mantle regeneration in the pearl oyster Pinctada maxima. Oysters were anaesthetised with 2.5 mL L(-1) prophylene phenoxetol prior to a piece of tissue (approximately 10 x 30 mm(2)) being excised from the ventral region of the mantle. In the first experiment, 56 oysters with mean (+/-SD) dorso-ventral measurement (DVM) of 125.5 +/- 8.9 mm had tissue excised from either the right mantle lobe, left mantle lobe or both mantle lobes. Following a further three month period in suspended culture, oyster survival was recorded and two oysters were selected arbitrarily from each group to be sacrificed for histological examination of healed mantle. In the second experiment 36 oysters with mean (+/-SD) DVM of 151.6 +/- 13.4 mm were used for excision of the distal part of the ventral region of the left mantle lobe. Two oysters were sampled at 1, 3, 6, 12, 24, 36, 48, 72 and 120 h (5 days) after mantle excision, and then at 12, 24, 45, 72 and 90 d after mantle excision for histological and histochemical analysis of mantle regeneration. There was almost 100 percent survival in both experiments. Healing and regeneration of mantle tissue in oysters subject to excision from the left, right or both mantle lobes was evident, with regenerated mantle appearing similar to non-regenerated mantle. All external and internal components of non-regenerated mantle were present in regenerated mantle tissue. Epithelization signifying wound healing occurred within 36-72 h and was characterised by a reduced wound area, haemocyte infiltration and accumulation, and cell dedifferentiation. Within 48 h of mantle excision, the latero-ventral edges of the wound flexed dorsally and attached to the dorsal edge of the wound reducing the wound area. Between five and twelve days after excision, the distal part of the mantle had divided into three small lobes which developed into the outer, middle and inner mantle folds two weeks later. Ninety days after excision the mantle had completely regenerated with histological observations indicating no difference in epithelial structure or in other internal mantle accessories when compared to non-regenerated mantle. Shell material began to be secreted onto the shell by regenerating mantle twelve days after excision. Initially this occurred in a position dorsal to the non-injured mantle edge. However, forty-five days after mantle excision, regenerated mantle had extended ventrally to a position similar to that of non-injured mantle. Nacre deposition by regenerated mantle had now reached the same position ventrally as that of non-injured mantle indicating full acquisition of nacre secreting abilities by regenerated mantle.

Quantitative analysis of antennal mosaic generation in Drosophila melanogaster by the MARCM system

Mosaics have been used in Drosophila to study development and to generate mutant structures when a mutant allele is homozygous lethal. New approaches of directed somatic recombination based on FRT/FLP methods, have increased mosaicism rates but likewise multiple clones in the same individual appeared more frequently. Production of single clones could be essential for developmental studies; however, for cell-autonomous gene function studies only the presence of homozygous cells for the target recessive allele is relevant. Herein, we report the number and extension of antennal mosaics generated by the MARCM system at different ages. This information is directed to obtain the appropriated mosaic type for the intended application. By applying heat shock at 10 different developmental stages from 0-12 h to 6-7 days after egg laying, more than 50% of mosaics were obtained from 5,028 adults. Single recombinant clones appeared mainly at early stages while massive recombinant areas were observed with late treatments.