Monitoring of collagen and collagen fragments in chromatography of protein mixtures

A new method for the detection of collagen and collagen peptides in the presence of other proteins is described. The procedure is based on alkaline hydrolysis of the proteins and monitoring of the free hydroxyproline after chromophore formation. The method is quick and sensitive and the color yield of hydroxyproline is not affected by chromatography solvents. As all steps of the assay take place in a single test tube the method is suitable for batch processing of column fractions. Due to the high sensitivity of the assay it can be used for the analysis of collagen and collagen peptides in extracts of small tissue samples or biopsies.     

Female collared flycatchers adjust yolk testosterone to male age, but not to attractiveness

The differential allocation hypothesis predicts that femalesinvest more resources into reproduction when mating with attractivemales. In oviparous animals this can include prefertilizationdecisions such as the production of larger eggs and the depositionof hormones, such as the steroid testosterone, into yolks. Onthe other hand, a compensatory hypothesis posits that femalesallocate more resources into the eggs when mated with malesof inferior quality. In the present study, we show that free-livingfemales of the collared flycatcher (Ficedula albicollis), asmall passerine bird, do not produce larger eggs or depositmore testosterone into eggs when mating with attractive malesreflected by a large forehead patch size, which is contraryto the prediction of the differential allocation hypothesis.However, we found higher yolk testosterone concentrations ineggs laid for young than older males. Because in young malesgenetic quality, parental experience, or willingness to investinto paternal care is likely to be low, high yolk testosteronelevel in their clutches may indicate that their females followa compensatory tactic. They may elicit more paternal care fromyoung, inexperienced males by hormonally increasing nestlingbegging. Laying date was also correlated with yolk testosteronelevel; however, when we controlled for it, male age still remaineda strong determinant of testosterone allocation.     

Growth factor-like phospholipids generated after corneal injury

The present study provides evidence that growth factor-likeglycerophosphate mediators of the lysophosphatidic acid (LPA) familyare present in the aqueous humor and the lacrimal gland fluid of therabbit eye. By use of a combination of HPLC, two-dimensional TLC, massspectrometry, and the Xenopus oocytebioassay, the LPA-like phospholipids LPA, cyclic PA,alkenyl-glycerophosphate (GP), lysophosphatidylserine, and phosphatidicacid were detected as physiological constituents of the fluids bathingthe cornea. Corneal injury resulted in an increased production of someof these mediators. Alkenyl-GP, a novel member of the LPA family, hasbeen identified in postinjury aqueous humor, establishing that it isgenerated endogenously. LPA and its homologues were found to bemitogenic in freshly dissociated keratocytes from uninjured corneas.There appears to be a link between the occurrence of LPA responsivenessin keratocytes activated by injury and the increase in LPA-likeactivity in aqueous humor. These data suggest that LPA and itshomologues are involved in maintaining the integrity of the normalcornea and in promoting cellular regeneration of the injured cornea.

     

Selection of reliable reference genes for qPCR studies on chondroprotective action

Background  

Chondroprotective agents (CPA) such as glucosamine, curcumin and diacerein represent potential remedies for the management of osteoarthritis and several studies have been performed on their effects in-vitro and in-vivo. For the investigation of chondroprotective action on chondrocyte gene expression, quantitative real-time RT-PCR is the method of choice. However, validation of applied normalization strategies represents a crucial and sometimes neglected step in the analysis process. Therefore, the present study aimed to determine the expression stability of common reference genes (ACTB, Beta actin; GAPDH, Glyceraldehyde-3-phosphate; B2M, Beta-2-microglobulin; HPRT1, Hypoxanthine phosphoribosyl-transferase I; SDHA, Succinate dehydrogenase complex, subunit A; YWHAZ, Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, zeta polypeptide) under the influence of glucosamine, curcumin and diacerein in the IL-1β-stimulated C-28/I2 chondrocyte model, using the geNorm software tool.     

The evolution of protein domains and the organizational complexities of metazoans

There is an increasingly heated debate on the very existence of a 'universe of exons' and on the types of genomes that existed after the RNA world. What has been lost in the excitement are the biological issues that relate to the rapid emergence of phenotypic novelties. These issues can be examined by integrating data on protein domains and genomic evolution with the geochemical and palaeontological records.