The study of Priapulus caudatus reveals conserved molecular patterning underlying different gut morphogenesis in the Ecdysozoa

Background The digestive systems of animals can become highly specialized in response to their exploration and occupation of new ecological niches. Although studies on different animals have revealed commonalities in gut formation, the model systems Caenorhabditis elegans and Drosophila melanogaster, which belong to the invertebrate group Ecdysozoa, exhibit remarkable deviations in how their intestines develop. Their morphological and developmental idiosyncrasies have hindered reconstructions of ancestral gut characters for the Ecdysozoa, and limit comparisons with vertebrate models. In this respect, the phylogenetic position, and slow evolving morphological and molecular characters of marine priapulid worms advance them as a key group to decipher evolutionary events that occurred in the lineages leading to C. elegans and D. melanogaster. Results In the priapulid Priapulus caudatus, the gut consists of an ectodermal foregut and anus, and a mid region of at least partial endodermal origin. The inner gut develops into a 16-cell primordium devoid of visceral musculature, arranged in three mid tetrads and two posterior duplets. The mouth invaginates ventrally and shifts to a terminal anterior position as the ventral anterior ectoderm differentially proliferates. Contraction of the musculature occurs as the head region retracts into the trunk and resolves the definitive larval body plan. Despite obvious developmental differences with C. elegans and D. melanogaster, the expression in P. caudatus of the gut-related candidate genes NK2.1, foxQ2, FGF8/17/18, GATA456, HNF4, wnt1, and evx demonstrate three distinct evolutionarily conserved molecular profiles that correlate with morphologically identified sub-regions of the gut. Conclusions The comparative analysis of priapulid development suggests that a midgut formed by a single endodermal population of vegetal cells, a ventral mouth, and the blastoporal origin of the anus are ancestral features in the Ecdysozoa. Our molecular data on P. caudatus reveal a conserved ecdysozoan gut-patterning program and demonstrates that extreme morphological divergence has not been accompanied by major molecular innovations in transcriptional regulators during digestive system evolution in the Ecdysozoa. Our data help us understand the origins of the ecdysozoan body plan, including those of C. elegans and D. melanogaster, and this is critical for comparisons between these two prominent model systems and their vertebrate counterparts

The Effect of DPG and IHP on the Relative Thermodynamic Affinity for CO of the Subunits of Rabbit Hemoglobin

The two chains of most hemoglobins interact differently with ligands as can be seen in two nmr resonances for bound ^(13)CO (Moon and Richards, 1972). This observation has led to interest in the possibility that the two chains have different thermodynamic affinities toward ligands (Huestis and Raftery, 1973, 1975; Moon and Richards, 1974; Huang and Redfield, 1976; Viggiano and Ho, 1979a,b). Rabbit hemoglobin possesses an unusual α-chain which causes ^(13)CO bound to it to have a different chemical shift than ^(13)CO bound to β chains (Moon and Richards, 1972, 1974) and, thereby, allows direct quantitative observation of the degree of ligation of the two subunits

Active immunization of Japanese quail hens with a recombinant chicken inhibin fusion protein enhances production performance

The effects of active immunization against inhibin on production performance in female Japanese quail (Coturnix coturnix japonica) were assessed in two separate trials using an MBP-cINA521 fusion protein as an immunogen. The fusion protein, MBP-cINA521, consisted of the bacterial maltose binding protein (MBP) and a truncated form of the mature α-subunit of chicken inhibin (cINA521). MBP-cINAl521 was constructed by: 1) excising a 521-bp PstI fragment from a chicken inhibin α-subunit cDNA (cINA6; gift of P. A. Johnson), 2) cloning this fragment, which encodes all but the first 11 amino acid residues of the mature α-subunit, into the pMal-c2 vector of the MBP fusion expression system, and 3) expressing the fusion protein (MBP-cINA521) from the Escherichia coli and purifying it using affinity chromatography. In each trial, quail were randomly and equally assigned to one of two injection treatments as follows: 1) MBP-cINA521 in Freund\u27s adjuvant, or 2) Freund\u27s adjuvant (vehicular controls; CON). All immunizations were given subcutaneously and Freund\u27s complete and incomplete adjuvant were used for primary and booster injections, respectively. In Trial 1, birds were given a primary challenge of 0.2 mg MBP-cINA521 per bird at 25 d of age, followed by booster immunizations (0.1 mg MBP-cINA521 per bird) at 33, 40, 47, 54 and 61 d of age and every 35 d thereafter. The CON birds received vehicular immunizations at the same time intervals. In Trial 2, birds treated with MBP-cINA521 received a primary challenge of 0.2 mg MBP-cINA521 per bird at 26 d of age, followed by booster immunizations (0.1 mg MBP-cINA521 per bird) using the same schedule as that used in Trial 1, with the exception that no boosters were given after 61 d of age. The CON birds received vehicular immunizations at the same time intervals. Collection of production performance data was initiated coincident with the laying of the first egg in each trial (i.e., beginning at 41 and 44 d of age for Trials 1 and 2, respectively) and continued for 30 1-wk periods of lay. Combined data from Trials 1 and 2 indicated that the mean ± SE age at first egg lay was markedly decreased (P \u3c 0.005) in MBP-cINA521-treated quail (53.4 ± 0.9 d of age) when compared to the CON (57.6 ± 1.3 d of age). Likewise, the mean ± SE age at 50% egg production was reduced (P \u3c 0.03) in quail immunized against inhibin (65.4 ± 2.1 d of age) when compared to the CON (77.6 ± 4.7 d of age). Total hen-day egg production was also higher (P \u3c 0.05, Trial 1; P \u3c 0.01, Trial 2) in MBP-cINA521-treated quail (88.7 ± 1.4%, Trial 1; 90.1 ± 1.2%, Trial 2) than in the CON birds (81.9 ± 2.9%, Trial 1; 73.6 ± 6.5%, Trial 2). Collectively, these findings provide evidence that inhibin immunoneutralization accelerated puberty and enhanced hen-day egg production during a 30-wk period of egg lay in Japanese quail

Recommendations for the design and analysis of epigenome-wide association studies

Epigenome-wide association studies (EWAS) hold promise for the detection of new regulatory mechanisms that may be susceptible to modification by environmental and lifestyle factors affecting susceptibility to disease. Epigenome-wide screening methods cover an increasing number of CpG sites, but the complexity of the data poses a challenge to separating robust signals from noise. Appropriate study design, a detailed a priori analysis plan and validation of results are essential to minimize the danger of false positive results and contribute to a unified approach. Epigenome-wide mapping studies in homogenous cell populations will inform our understanding of normal variation in the methylome that is not associated with disease or aging. Here we review concepts for conducting a stringent and powerful EWAS, including the choice of analyzed tissue, sources of variability and systematic biases, outline analytical solutions to EWAS-specific problems and highlight caveats in interpretation of data generated from samples with cellular heterogeneity.SCOPUS: re.jinfo:eu-repo/semantics/publishe