Ocular anomaly in Atlantic midshipman Porichthys plectrodon (Batrachoidiformes: Batrachoididae) from the Mississippi Canyon, north-central Gulf of Mexico.

The first record of an ocular anomaly in Atlantic midshipman Porichthys plectrodon (Batrachoidiformes: Batrachoididae) is reported from a specimen captured in the Mississippi Canyon. The anomalous specimen was bilaterally anophthalmic and the nape and dorsum were darkly pigmented but alizarin staining and histology revealed a complete eye embedded within the cranium beneath a markedly thickened dermal component of the cornea, along with seemingly minor elaboration of the choroid rete between the cornea and lens. Aetiology is indeterminate and beyond the scope of the study materials but barotrauma, infectious disease and previous wounding are doubtful.

Genetic studies in the Nigerian population implicate an MSX1 mutation in complex oral facial clefting disorders.

BACKGROUND: Orofacial clefts are the most common malformations of the head and neck, with a worldwide prevalence of 1 in 700 births. They are commonly divided into CL(P) and CP based on anatomic, genetic, and embryologic findings. A Nigerian craniofacial anomalies study (NigeriaCRAN) was set up in 2006 to investigate the role of gene-environment interaction in the origin of orofacial clefts in Nigeria. SUBJECTS AND METHODS: DNA isolated from saliva from Nigerian probands was used for genotype association studies and direct sequencing of cleft candidate genes: MSX1 , IRF6 , FOXE1, FGFR1 , FGFR2 , BMP4 , MAFB, ABCA4 , PAX7, and VAX1 , and the chromosome 8q region. RESULTS: A missense mutation A34G in MSX1 was observed in nine cases and four HapMap controls. No other apparent causative variations were identified. Deviation from Hardy Weinberg equilibrium (HWE) was observed in these cases (p = .00002). A significant difference was noted between the affected side for unilateral CL (p = .03) and bilateral clefts and between clefts on either side (p = .02). A significant gender difference was also observed for CP (p = .008). CONCLUSIONS: Replication of a mutation previously implicated in other populations suggests a role for the MSX1 A34G variant in the development of CL(P).

First record of a digenean from invasive lionfish, Pterois cf. volitans, (Scorpaeniformes: Scorpaenidae) in the northwestern Atlantic Ocean.

Adults of Lecithochirium floridense (Digenea: Hemiuridae) parasitized the stomach in each of 22 necropsied lionfish, Pterois cf. volitans (Scorpaeniformes: Scorpaenidae) (prevalence  =  100%, mean intensity  =  11), captured in the northwestern Atlantic Ocean off Beaufort, North Carolina (34°14.83'N, 76°35.25'W). This is the first report of a digenean from the invasive lionfish and that of L. floridense from a species of Pterois. The leech specimen previously identified as Myzobdella lugubris from P. volitans in the northwestern Atlantic Ocean is re-identified as Trachelobdella lubrica based on a study of the original voucher specimen.

Lesions associated with plerocerci (Platyhelminthes: Cestoda: Trypanorhyncha) in the gastric wall of a cownose ray, Rhinoptera bonasus (Mitchill), (Myliobatiformes: Rhinopteridae) from the northern Gulf of Mexico.

We describe lesions associated with a seemingly intense infection of trypanorhynch plerocerci (Platyhelminthes: Cestoda: Trypanorhyncha) in the gastric wall of a female cownose ray, Rhinoptera bonasus (Myliobatiformes: Rhinopteridae) captured in the northern Gulf of Mexico. Grossly, the multitude of encapsulated, encysted plerocerci imparted a bumpy and cobbled appearance to the serosa of the stomach, and none was observed in any other tissue during routine parasitological necropsy. Histologically, the plerocerci were associated with severe intramural granulomatous gastritis, vascular ectasia and mesothelial polyposis with the exclusion of the mucosa. To our knowledge, this is the first published case study documenting platyhelminth-associated histopathological changes in the gastrointestinal tract of R. bonasus as well as that of the efficacy of immunocytochemical markers for smooth muscle actin, Factor VIII, S-100, and proliferating cell nuclear antigen in Myliobatiformes. It also may serve as a potential primer for much needed ecological investigations regarding the potential role of elasmobranchs as intermediate or 'paratenic' hosts in the life cycles of trypanorhynch cestodes.

Gill lesions associated with Erpocotyle tiburonis (Monogenea: Hexabothriidae) on wild and aquarium-held bonnethead sharks (Sphyrna tiburo).

Gill lesions associated with infections of Erpocotyle tiburonis (Brooks, 1934) (Monogenea: Hexabothriidae) on wild bonnethead sharks (Sphyrna tiburo (L., 1758) (Carcharhiniformes: Sphyrinidae)) were compared with those on aquarium-held ones using light and scanning electron microscopy. Uninfected gill filaments had slender, triangular, smooth-surfaced lamellae and interlamellar water channels that were approximately equal in size. Four wild sharks were each infected by 3-11 widely separated adult E. tiburonis, and 1 of these sharks hosted a juvenile specimen. Lamellae flanking or touching adult E. tiburonis were pushed aside or bent, but were otherwise identical to those of uninfected filaments. Two aquarium-held sharks were each infected by hundreds of juvenile and adult E. tiburonis. In these sharks, lamellae near juveniles were pushed apart or bent, but were otherwise normal, whereas a thick, ragged-surfaced layer of hyperplastic epithelium both filled interlamellar water channels and partially or completely covered lamellae near adults. Results of this study suggest that the intense infections of E. tiburonis were facilitated by captivity and caused severe hyperplastic lesions that ultimately led to the death of the sharks by reducing or blocking the respiratory water flow over lamellae and thus reducing the exchange of gases and ions across the lamellar epithelium. In contrast, the wild sharks were infected by fewer worms and exhibited relatively minor lesions.

Kroeyerina deetsorum n. sp. (Copepoda: Kroyeriidae) from the olfactory sacs of Atlantic sharpnose sharks (Rhizoprionodon terraenovae) captured in the Gulf of Mexico and northwestern Atlantic and first report of copepodids representing Kroyeriidae.

Kroeyerina deetsorum n. sp. (Copepoda: Kroyeriidae) is described from female and male specimens collected from the olfactory sacs of Atlantic sharpnose sharks, Rhizoprionodon terraenovae (Richardson, 1836), captured in the Gulf of Mexico and northwestern Atlantic. Kroeyerina deetsorum is easily distinguished from known congeners by the extremely small size of its adults (i.e., females about 1.2 mm total length and males about 1.0 mm total length). Kroeyerina deetsorum is also distinguished from its congeners by possessing a subquadrate rostrum without lobes or upturned horns. It is suspected that K. deetsorum belongs to a clade within Kroeyerina whose members only infect sharks. This report also provides first descriptions of a nauplius representing Kroeyerina and copepodids representing Kroyeriidae. The early-stage copepodid of K. deetsorum lacks a frontal organ and frontal filament and uses its chelate antennae to attach to its host.

Calicotyle californiensis n. sp. and Calicotyle urobati n. sp. (Monogenea: Calicotylinae) from elasmobranchs in the Gulf of California.

Two new species of Calicotyle (Monocotylidae: Calicotylinae) are described from elasmobranchs in the western Gulf of California. Calicotyle californiensis n. sp. is described from a single specimen collected from a gray smoothhound shark (Mustelus californicus, Carcharhiniformes: Triakidae). It is distinguished from its congeners by the combination of having vaginal pores opening within the intercecal space, distal regions of the vaginae twisting, proximal regions of the vaginae fusing medially to form a kidney bean-shaped structure, and a relatively long male copulatory organ recurving 3 times and passing between the distal penis bulb and the seminal vesicle. Calicotyle urobati n. sp. is described from 16 specimens collected from at least the cloaca and rectum of the round rays Urobatis halleri and Urobatis maculatus (Rajiformes: Urolophidae). It is distinguished from its congeners by the combination of having vaginal pores opening outside the intercecal space and proximal regions of the vaginae terminating at the level of the ceca. Members of Calicotyle have not been reported previously from the eastern Pacific Ocean or from these hosts. In the past, species of Calicotyle have been distinguished based primarily on the shape and length of the male copulatory organ and hamuli. Divisions of the vaginae and the positions of the vaginal pores are also useful in distinguishing members of the genus.

Pharmaceutical care of postoperative nausea and vomiting: balanced scorecard for outcomes.

Using the balanced scorecard to measure outcomes, a multidisciplinary team worked to improve antiemetic therapy and decrease postoperative nausea and vomiting. Patient satisfaction measures were nausea and pain scales (10 cm, nonnumbered, visual analog). The quality measure was number of vomiting episodes. Cost measures were length of postoperative stay and antiemetic requirement. Institutional learning was assessed by spread of prescribing changes beyond the first cohort of patients. Intervention subjects were providers of general anesthesia in two cohorts of patients (60 and 346) undergoing laparoscopic cholecystectomy. Outcome assessment revealed low nausea and vomiting scores throughout the study, and antiemetic use decreased 50%. There were no deteriorations in pain scores or length of stay. Balanced scorecard measurements suggest no adverse unintended outcomes consequent to changes in prescribing behavior. Balanced scorecard processes assisted consensus among pharmacists, nurses, and physicians that may have accelerated behavioral changes.

Skin lesions caused by Dermophthirius penneri (Monogenea: Microbothriidae) on wild-caught blacktip sharks (Carcharhinus limbatus).

Skin lesions caused by the ectoparasite Dermophthirius penneri Benz, 1987 (Monogenea: Microbothriidae) on 2 wild-caught blacktip sharks (Carcharhinus limbatus) from the northern Gulf of Mexico were studied using light and scanning electron microscopy. Grossly, lesions appeared as multifocal, well-demarcated, ovoid or irregularly shaped, light gray patches of skin. Scanning electron microscopy of lesions revealed gaps between placoid scales apparently created by detachment and loss of placoid scales, rotated and tilted placoid scales with blunt distal tips and shallow ridges, and a frayed epithelium that covered some placoid scales and filled some spaces between placoid scales. Light microscopy of lesions revealed epithelial hyperplasia accompanied by dermal infiltrates of moderate numbers of loosely arranged lymphocytes interposed between collagen bundles in the superficial layers of the stratum compactum. This report provides the first details of microbothriid skin lesions on wild sharks. Our results indicate that D. penneri caused chronic skin lesions not associated with bacterial infection or severe, debilitating, skin disease in the studied sharks.

Margolisius abditus n. gen., n. sP. (Copepoda: Lernaeopodidae) from gill lamellae of a remora (Remora remora) collected in the Gulf of California.

Margolisius abditus n. gen., n. sp. (Copepoda: Lernaeopodidae) is described from female specimens collected from gill lamellae of a remora, Remora remora (L.), captured in the Gulf of California near Punta Arena, Baja California. Comparison of this species with 13 lernaeopodid genera with which it shares (a) absence of posterior trunk processes; (b) presence of a relatively long cylindrical cephalothorax, usually reflected along the dorsal surface of the trunk; and (c) a marine habitat showed that it cannot be placed in any of them, thus necessitating establishment of a new genus. Margolisius abditus n. sp. is the smallest known lernaeopodid species, its ovigerous females measuring about 0.5 mm in total length.

Dionchus postoncomiracidia (Monogenea: Dionchidae) from the skin of blacktip sharks, Carcharhinus limbatus (Carcharhinidae).

Postoncomiracidia of Dionchus sp. are described from specimens collected from the skin of 2 blacktip sharks Carcharhinus limbatus, captured in the northern Gulf of Mexico. The parasites resemble nonciliated oncomiracidia hatched from eggs laid by Dionchus sp. on gills of a cobia Rachycentron canadum and adults of Dionchus remorae that were collected from gills of a common sharksucker Echeneis naucrates, captured in association with a third blacktip shark. The hamuli of the postoncomiracidia were morphologically similar to those of adult D. remorae. This is the first report of dionchids from an elasmobranch and from a location other than the gills. These findings support the idea that some dionchid oncomiracidia colonize the skin of sharks or other aquatic vertebrates that sponsor remoras, prior to transferring to other remoras and maturing.

Coordination of the initiation of recombination and the reductional division in meiosis in Saccharomyces cerevisiae.

Early exchange (EE) genes are required for the initiation of meiotic recombination in Saccharomyces cerevisiae. Cells with mutations in several EE genes undergo an earlier reductional division (MI), which suggests that the initiation of meiotic recombination is involved in determining proper timing of the division. The different effects of null mutations on the timing of reductional division allow EE genes to be assorted into three classes: mutations in RAD50 or REC102 that confer a very early reductional division; mutations in REC104 or REC114 that confer a division earlier than that of wild-type (WT) cells, but later than that of mutants of the first class; and mutations in MEI4 that do not significantly alter the timing of MI. The very early mutations are epistatic to mutations in the other two classes. We propose a model that accounts for the epistatic relationships and the communication between recombination initiation and the first division. Data in this article indicate that double-strand breaks (DSBs) are not the signal for the normal delay of reductional division; these experiments also confirm that MEI4 is required for the formation of meiotic DSBs. Finally, if a DSB is provided by the HO endonuclease, recombination can occur in the absence of MEI4 and REC104.

Molecular and genetic analysis of REC103, an early meiotic recombination gene in yeast.

In the yeast Saccharomyces cerevisiae at least 10 genes are required to begin meiotic recombination. A new early recombination gene REC103 is described in this paper. It was initially defined by the rec103-1 mutation found in a selection for mutations overcoming the spore inviability of a rad52 spo13 haploid strain. Mutations in REC103 also rescue rad52 in spo13 diploids. rec103 spo13 strains produce viable spores; these spores show no evidence of meiotic recombination. rec103 SPO13 diploids produce no viable spores, consistent with loss of recombination. Mutations in REC103 do not affect mitotic recombination, growth, or repair. These phenotypes are identical to those conferred by mutations in several other early meiotic recombination genes (e.g., REC102, REC104, REC114, ME14, MER2, and SPO11). REC103 maps to chromosome VII between ADE5 and RAD54. Cloning and sequencing of REC103 reveals that REC103 is identical to SK18, a gene that depresses the expression of yeast double-stranded ("killer") (ds)RNA viruses. REC103/SK18 is transcribed in mitotic cells and is induced approximately 15-fold in meiosis. REC103 has 26% amino acid identity to the Schizasaccharomyces pombe rec14+ gene; mutations in both genes confer similar meiotic phenotypes, suggesting that they may play similar roles in meiotic recombination.

Recombination and the progression of meiosis in Saccharomyces cerevisiae.

Recombination is an essential part of meiosis: in almost all organisms, including Saccharomyces cerevisiae, proper chromosome segregation and the viability of meiotic products is dependent upon normal levels of recombination. In this article we examine the kinetics of the meiotic divisions in four mutants defective in the initiation of recombination. We find that mutations in any of three Early Exchange genes (REC104, REC114 or REC102) confer a phenotype in which the reductional division occurs earlier than in an isogenic wild-type diploid. We also present data confirming previous reports that strains with a mutation in the Early Exchange gene. MEI4 undergo the first division at about the same time as wild-type cells. The rec104 mutation is epistatic to the mei4 mutation for the timing of the first division. These observations suggest a possible relationship between the initiation of recombination and the timing of the reductional division. These data also allow these four Early Exchange genes examined to be distinguished in terms of their role in coordinating recombination with the reductional division.

Isolation of early meiotic recombination genes analogous to S. cerevisiae REC104 from the yeasts S. paradoxus and S. pastorianus.

The REC104 gene of Saccharomyces cerevisiae is required to initiate recombination in meiosis. Mutations in REC104 eliminate meiotic recombination and lead to the production of inviable spores. To determine if analogous genes exist in other yeasts, clones that hybridized to a REC104 probe were isolated from the yeasts S. paradoxus and S. pastorianus. When transformed into a rec104 strain, the REC104 analogs from these two yeasts restored spore viability and meiotic recombination to the same level as a REC104 gene cloned from S. cerevisiae. Compared to S. cerevisiae, the S. paradoxus gene codes for 79% identical amino acids and has 86% nucleic-acid identity in the promoter region and 84% in the coding region. The S. pastorianus gene codes for 63% identical amino acids and has 59% and 71% identity in the promoter and the coding regions, respectively.

Double strand breaks at the HIS2 recombination hot spot in Saccharomyces cerevisiae.

Double strand breaks (DSBs) have been found at several meiotic recombination hot spots in Saccharomyces cerevisiae; more global studies have found that they occur at many places along several yeast chromosomes during meiosis. Indeed, the number of breaks found is consistent with the number of recombination events predicted from the genetic map. We have previously demonstrated that the HIS2 gene is a recombination hot spot, exhibiting a high frequency of gene conversion and associated crossing over. This paper shows that DSBs occur in meiosis at a site in the coding region and at a site downstream of the HIS2 gene and that the DSBs are dependent upon genes required for recombination. The frequency of DSBs at HIS2 increases when the gene conversion frequency is increased by alterations in the DNA around HIS2, and vice versa. A deletion that increases both DSBs and conversion can stimulate both when heterozygous; that is, it is semidominant and acts to stimulate DSBs in trans. These data are consistent with the view that homologous chromosomes associate with each other before the formation of the DSBs.

Analysis of a recombination hotspot for gene conversion occurring at the HIS2 gene of Saccharomyces cerevisiae.

The properties of gene conversion as measured in fungi that generate asci containing all the products of meiosis imply that meiotic recombination initiates at specific sites. The HIS2 gene of Saccharomyces cerevisiae displays a high frequency of gene conversion, indicating that it is a recombination hotspot. The HIS2 gene was cloned and sequenced, and the cloned DNA was used to make several different types of alterations in the yeast chromosome by transformation; these alterations were used to determine the location of the sequences necessary for the high levels of meiotic conversion observed at HIS2. Previous work indicated that the gene conversion polarity gradient is high at the 3' end of the gene, and that the promoter of the gene is not necessary for the high frequency of conversion observed. Data presented here suggest that at least some of the sequences necessary for high levels of conversion at HIS2 are located over 700 bp downstream of the end of the coding region, extend over (at least) several hundred base pairs, and may be quite complex, perhaps involving chromatin structure. Additional data indicate that multiple single base heterologies within a 1-kb interval contribute little to the frequency of gene conversion. This contrasts with other reports about the role of heterologies at the MAT locus.