Convergent evolution of parrot plumage coloration.

Parrots have remarkable plumage coloration that result in part from a unique ability to produce pigments called psittacofulvins that yield yellow to red feather colors. Little is known about the evolution of psittacofulvin-based pigmentation. Widespread color mutations of captive-bred parrots provide perfect opportunities to study the genetic basis of this trait. An earlier study on blue budgerigars, which do not possess psittacofulvins, reveals the involvement of an uncharacterized polyketide synthase (MuPKS) in yellow psittacofulvin synthesis. The blue phenotype had repeatedly appeared in different parrot species, similar to independent experimental replications allowing the study of convergent evolution and molecular mechanism of psittacofulvin-based pigmentation. Here, we investigated the genetic basis of the blue phenotypes in two species of Agapornis parrots, Fischer's lovebird (A. fischeri) and Yellow-collared lovebird (A. personatus). Using whole-genome data, we identified a single genomic region with size <2 Mb to be strongly associated with the color difference between blue and wild-type (WT) birds in both species. Surprisingly, we discovered that the mutation associated with the blue Agapornis phenotype was identical to the previously described substitution causing the functional change of MuPKS in budgerigars. Together with the evidence of shared blue-associated haplotypes and signatures of a selective sweep in this genomic region in both species, we demonstrated both de novo mutation and interspecific introgression play a role in the evolution of this trait in different Agapornis species. The convergent substitution in the same gene in both lovebirds and budgerigars also indicates a strong evolutionary constraint on psittacofulvin-based coloration.

Impairment of mixed melanin-based pigmentation in parrots.

Parrots and allies (Order Psittaciformes) have evolved an exclusive capacity to synthesize polyene pigments called psittacofulvins at feather follicles, which allows them to produce a striking diversity of pigmentation phenotypes. Melanins are polymers constituting the most abundant pigments in animals, and the sulphurated form (pheomelanin) produces colors that are similar to those produced by psittacofulvins. However, the differential contribution of these pigments to psittaciform phenotypic diversity has not been investigated. Given the color redundancy, and physiological limitations associated with pheomelanin synthesis, we hypothesized that the latter would be avoided by psittaciform birds. Here, we tested this using Raman spectroscopy to identify pigments in feathers exhibiting colors suspected of being produced by pheomelanin (i.e. dull red, yellow, greyish-brown and greenish-brown) in 26 species from the three main lineages of Psittaciformes. We detected the non-sulphurated melanin form (eumelanin) in black, grey and brown plumage patches, and psittacofulvins in red, yellow and green patches, but there was no evidence of pheomelanin. As natural melanins are assumed to be composed of eumelanin and pheomelanin in varying ratios, our results represent the first report of impairment of mixed melanin-based pigmentation in animals. Given that psittaciforms also avoid the uptake of circulating carotenoid pigments, these birds seem to have evolved a capacity to avoid functional redundancy between pigments, likely by regulating follicular gene expression. Our study provides the first vibrational characterization of different psittacofulvin-based colors and thus helps to determine the relative polyene chain length in these pigments, which is related to their antireductant protection activity.

Impairment of mixed melanin-based pigmentation in parrots.

Parrots and allies (Order Psittaciformes) have evolved an exclusive capacity to synthesize polyene pigments called psittacofulvins at feather follicles, which allows them to produce a striking diversity of pigmentation phenotypes. Melanins are polymers constituting the most abundant pigments in animals, and the sulphurated form (pheomelanin) produces colors that are similar to those produced by psittacofulvins. However, the differential contribution of these pigments to psittaciform phenotypic diversity has not been investigated. Given the color redundancy, and physiological limitations associated to pheomelanin synthesis, we hypothesized that the latter would be avoided by psittaciform birds. Here we test this by using Raman spectroscopy to identify pigments in feathers exhibiting colors suspicious of being produced by pheomelanin (i.e., dull red, yellow and grey- and green-brownish) in 26 species from the three main lineages of Psittaciformes. We detected the non-sulphurated melanin form (eumelanin) in black, grey and brown plumage patches, and psittacofulvins in red, yellow and green patches, but no evidence of pheomelanin. As natural melanins are assumed to be composed of eumelanin and pheomelanin in varying ratios, our results represent the first report of impairment of mixed melanin-based pigmentation in animals. Given that psittaciforms also avoid the uptake of circulating carotenoid pigments, these birds seem to have evolved a capacity to avoid functional redundancy between pigments, likely by regulating follicular gene expression. Ours study provides the first vibrational characterization of different psittacofulvin-based colors and thus helps to determine the relative polyene chain length in these pigments, which is related to their antireductant protection activity.

A shared medication scheme for community dwelling older patients with polypharmacy receiving home health care: role of the community pharmacist.

Background and objective: An accurate medication scheme may be a useful tool to improve medication safety in primary care. This study aimed to identify (1) pharmacists' alterations to nurse medication schemes and (2) potential improvements to the contribution of the community pharmacist to a shared medication scheme within a multidisciplinary collaboration. Dosing frequency, potentially incorrect moments of intake, drug-drug interactions and medication complexity (quantified by the Medication Regimen Complexity Index, MRCI) were investigated. Setting and method: Observational study in community dwelling older patients (≥70 years) with polypharmacy receiving home health care (i.e. medications being prepared and/or administered by home care nurses). Home care nurses provided the community pharmacist with the original medication scheme ('nurse medication scheme'), subsequently the community pharmacist generated a standardized 'pharmacist medication scheme' which was uploaded on an electronic health platform (Vitalink). The researcher recorded all pharmacists' alterations and looked for possible additional improvements ('researcher medication scheme'). Results: Pharmacists made 482 alterations to the nurse medication schemes of 31 patients. Most important alterations included adding indication (61%), generic or brand name (18%) and moment of intake (9%). Pharmacists did not reduce dosing frequency. MRCI scores (median [IQR]) significantly differed between pharmacist (38 [15]) and nurse medication schemes (32 [11]) (p < 0.001) and between nurse (32 [11]) and researcher medication schemes (40 [15]) (p < 0.001). Conclusion: Alterations made by the community pharmacists enable more complete and accurate medication schemes; however, there is room for improvement in optimizing the patient's medication scheme in a multidisciplinary collaboration.

Internal cognitive control in clinical depression: general but no emotion-specific impairments.

Prior research has suggested that depression is characterized by impaired cognitive control. The present study sought to investigate internal cognitive control impairments related to emotional information and task settings in clinical depression (MDD, major depressive disorder). Internal cognitive control was operationalized as switching between internally held mental representations that required continuous updating in working memory and measured with the Internal Shift Task (IST). The results showed that MDD individuals were characterized by a general switching impairment. This switching impairment was neither influenced by the task-relevance of emotional information, nor influenced by the valence of the faces within the emotion condition. The impairment in cognitive control reflected in general switching impairments was related to rumination, a specific cognitive symptom and important risk factor of depression. The results of this study offer new insights into the relationship between depression and impaired cognitive control with potential clinical implications, informing treatment and prevention programmes.