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At least 19 recordsLinked to original sources
PubMed1995

Spermatozoal ultrastructure in three species of parrots (aves, Psittaciformes) and its phylogenetic implications.

BACKGROUND: DNA-DNA hybridization studies suggest that Psittaciformes are highly, but not the most, derived nonpasserines. Multilocus protein electrophoresis indicates that cockatoos (Cacatuinae) form a monophyletic lineage distant from the other Australo-Papuan psittacids (Psittacinae). METHODS: Transmission electron microscope procedures are applied to the spermatozoa of three parrots, in the Cacatuninae and Psittacinae, to investigate these relationships. RESULTS: Psittaciform sperm have the following characteristics: (1) conical acrosome vesicle; rodlike perforatorium; cylindrical, highly condensed nucleus; proximal and distal centriole embedded in dense material; elongate periaxonemal mitochondrial midpiece, (2) nine dense peripheral axonemal fibers (coarse fibers), (3) no fibrous sheath around the axoneme, (4) mitochondria with linear cristae, lacking intra- (or inter-) mitochondrial dense bodies, (5) restriction of the endonuclear perforatorial canal to the anterior region of the nucleus, (6) a short distal centriole, and (7) nucleus abutting on but not penetrating the acrosome. CONCLUSIONS: (1) These features are tetrapod symplesiomorphies, (2) is an amniote synapomorphy; the fibers differ from those of reptiles in being uniform in size, (3) loss of the fibrous sheath is an apomorphy known elsewhere only in columbiforms, (4) are apomorphies relative to basal aminiotes (Chelonia, Sphenodon, and Crocodilia), (5) is an apomorphic condition shared with other nonpasserines (galliforms and the white-naped crane) and crocodilians, (6) the latter taxa differ from parrots in a plesiomorphic elongation of the distal centriole, and (7) is a unique apomorphy of parrot sperm relative to other nonpasserines and reptiles. The short midpiece of N. hollandicus distinguishes this cacatuine from the two psittacines.

Animals↗
PubMed1986

Interordinal conservatism of chromosome banding patterns in Gallus domesticus (Galliformes) and Melopsittacus undulatus (Psittaciformes).

Chromosome banding homologies were studied between the domestic chicken, Gallus domesticus (Galliformes), and the budgerigar, Melopsittacus undulatus (Psittaciformes). In spite of large karyological differences, the G-banding patterns were found to be conserved to a considerable extent between the two species. There were some differences in C- and Hoechst 33258/Q-banding patterns.

Animals↗
PubMedDate not supplied

Serological evaluation of some psittaciformes for budgerigar fledgling disease virus.

Breeding psittaciform birds (psittacines) from three geographically separated aviaries experiencing fledgling mortality were monitored during 1983 and 1984 for specific serum antibody to budgerigar fledgling disease virus (BFDV) using a fluorescent-antibody virus-neutralization test. Neither the time nor the extent of exposure to the virus was known. Serological titers were positive in 45% of birds sampled from Aviary 1, 25% from Aviary 2, and 11% from Aviary 3. Several species of psittacine birds within each aviary were serologically positive for BFDV. The results indicated that a papovavirus similar to BFDV appears to infect a wide range of captive adult psittacine birds. Macaws (Ara sp. and Anodorhynchus sp.) were evaluated for distribution of infection. Each species within these two genera showed positive serological titers to BFDV. Three groups of birds showed a decrease in serum antibody titer to BFDV at 1 and 2.5 months after the first sampling. Positive titers decreased from 66 to 20% for one group and from 60 to 50% for a second group in 1 month, and they decreased from 42 to 17% for a third group in 2.5 months.

Animals↗
PubMed1986

The early ontogeny of ventilation and homeothermy in an altricial bird, Agapornis roseicollis (Psittaciformes).

The body temperature (Tb) of brooded Agapornis nestlings increased with age from 36.2 on the day of hatching to 38.9 degrees C on day 11.5, whereas the thermally neutral ambient temperature (Ta,n) decreased with age. The Tb of nestlings after a 20 min exposure to Ta approximately equal to 5 degrees C less than Ta,n increased from 31.9 on day 0.5 to 37 degrees C on day 11.5. At Ta,n both resting VO2 and mass-independent resting VO2 increased with age. Ventilation frequency (f) at Ta,n increased with age from 14.9 br/min on day 0.5 to 65.6 on day 11.5. This trend is the opposite of the allometric prediction based upon data from adult birds. At hatching, tidal volume (VT) was larger than predicted allometrically, whereas minute volume (VI) was smaller. After 20 min exposure to Ta 5 degrees C less than Ta,n, f, VT, and VI in nestlings 1 to 3 days old remained unchanged, but VO2 and oxygen extraction efficiency decreased. This mild cold-challenge caused a transient increase in VO2 of nestlings 5 to 8 days of age and 20 to 35% of adult mass. By the time the nestlings were 11.5 days old and had a mass 44% that of adults, their metabolic response to a mild cold-challenge was equal to that of an adult of the same mass. However, they were not capable of effective homeothermy over a wide range of Ta's.

Aging↗
PubMed1976

[Fat-embolic vascular occlusions in avian lungs. Research of histologically determinable neutral fats in parrotlike birds (Psittaciformes)].

In 50 flying birds (49 parrot-like, one peacock), the content of fat-embolic vascular occlusions was determined. In 22 cases, fat-embolic occlusions of low intensity were found in pulmonary capillaries. There were no occlusions in renal vessels. The fat embolies had no influence on a lethal outcome. There was no statistically significant correlation between the fatty infiltration of the liver, the fat content of the bone marrow, and the frequency of fat-embolic occlusion of blood vessels. In 18 cases, mycoses were the cause of death. These infections did not influence the number of fat-embolic vascular occlusions.

Animals↗
PubMedDate not supplied

Neuropathic gastric dilatation in psittaciformes.

Psittacine neuropathic gastric dilatation was studied in four cockatoos (Cacatua spp.). The birds died with characteristic clinical signs, and post-mortem examination revealed a highly distended proventriculus. Upon light microscopic examination, most of the ganglia of the gastric plexus and some of the duodenal myenteric plexus appeared destroyed and replaced by round cell accumulations; the same was true for the celiac ganglion. The neuronal perikaryon of the celiac ganglion and the myenteric plexus revealed intranuclear and extranuclear eosinophilic inclusion bodies. The electron microscope revealed virus-like particles outside and within those inclusions. These particles were similar to particles described and identified as paramyxovirus.

Animals↗
PubMed1982

[Culicoides nubeculosus, an experimental vector of a new trypanosome from psittaciforms: Trypanosoma barkeri n. sp].

Two out of four Psittacula roseata from Thaïland harboured a trypanosome: T. bakeri n. sp. Laboratory reared Culicoides nubeculosus were fed on one of them. The trypanosomes developed well in this arthropod and metatrypomastigotes were observed five days after the blood meal. The inoculation of crushed Culicoides into one of the trypanosome-free Psittacula gave rise to a parasitaemia after a prepatent period of eleven days. This provides more evidence that Culicoides can act as vectors of avian trypanosomes.

Animals↗
PubMedDate not supplied

Salmonella enteritidis infection in two species of psittaciformes.

In 1990, Salmonella enteritidis phage type 4 was recovered from two young (less than 20-week-old) lilac-crowned Amazon parrots (Amazona finschi Schlater), one in Tennessee and one in Kansas. The parrot from Tennessee was treated for a plugged naris and anorexia before the S. enteritidis infection was discovered. The parrot from Kansas exhibited signs of septicemia and died within 24 hours of examination. An apparently healthy green-cheeked conure (Pyrrhura molinae) on the same premises as the parrot from Tennessee was positive for S. enteritidis phage type 4 on a cloacal swab. These are the first reported cases of avian infection with S. enteritidis phage type 4 in the United States. Because several infectious agents were present simultaneously in the Amazon parrots, it was difficult to determine the precise role of S. enteritidis phage type 4 in the clinical presentations.

Animals↗
PubMedDate not supplied

Prevalence of Campylobacter jejuni in selected domestic and wild birds in Louisiana.

Prevalence of Campylobacter jejuni was determined in a selected population of domestic and free-living birds submitted for necropsy to the Louisiana State Veterinary Medical Diagnostic Laboratory. The 445 cases examined included 13 orders of birds and yielded C. jejuni in 45 cases, representing an isolation rate of 10.1%. Prevalence was highest in Galliformes (25.2%), followed by Anseriformes (12.9%) and Columbiformes (8.3%). Only one isolation was made out of 179 Psittaciformes examined. Penner serotypes 1, 2, 4, and 16 were most commonly identified among the C. jejuni isolates. This study emphasizes the importance of Galliformes as reservoirs of C. jejuni. The commonality of these serotypes with isolates derived from humans suggests the zoonotic potential of Galliformes in relation to human campylobacteriosis. The isolation rate of 12.9% in Anseriformes implicates free-living and migratory waterfowl as carriers of C. jejuni. Results confirm that Psittaciformes represent a low risk of C. jejuni infection in humans.

Animals↗
PubMed1992

Highly repeated DNA sequences in birds: the structure and evolution of an abundant, tandemly repeated 190-bp DNA fragment in parrots.

Up to 6.8% of the parrot (Psittaciformes) genome consists of a tandemly repeated, 190-bp sequence (P1) located in the centromere of many if not all chromosomes. Monomer repeats from 10 different psittacine species representing four subfamilies were isolated and cloned. The intraspecific sequence variation ranged from 1.5 to 7%. The interspecific sequence variation ranged from less than 3% between two species of cockatoos to approximately 45% between cockatoos and other parrots. The monomer sequences of all 10 parrot species contained several conserved (> 90%) sequence elements at identical locations within the repeat. A comparison with tandemly repeated DNA sequences in other avian species showed that several of these conserved elements were also present at similar locations within the 184-bp repeat of the Chilean flamingo (Phoenicopterus chilensis), suggesting a great antiquity of the repeat. One of the elements was also found in the tandemly repeated sequences of the crane (Gruidae) and falcon (Falconidae) families. The data were used for the construction of a partial most parsimonious relationship that supports a regional subdivision of the Psittaciformes.

Animals↗
PubMed1994

Neurochemical specializations associated with vocal learning and production in songbirds and budgerigars.

Specialized neural circuitry has evolved in groups of birds where vocal learning is known to occur, such as in the oscine suborder of the Passeriformes (songbirds) and in the order Psittaciformes (parrots). These specializations are most prominent in the telencephalon, while the midbrain and medullary portions of the vocal control circuit are generally similar in all orders of birds. Specializations in songbirds have at least four components: 1) a set of distinct and interconnected vocal control nuclei in the forebrain; 2) unique connections between the auditory system and these vocal control nuclei; 3) the occurrence of receptors for sex steroid hormones in a subset of the vocal control nuclei; and 4) unique patterns in the distribution of various markers of the major classes of neurotransmitters within the vocal control nuclei. In the order Psittaciformes, as exemplified by budgerigars (Melopsittacus undulatus), it appears that neural specializations generally similar to those described in songbirds have evolved independently. Although anatomical studies have found a system of interconnected forebrain regions in budgerigars that are roughly similar to those described in oscines, detailed connectivity studies of this forebrain system suggest that it is only superficially similar to that of songbirds, and budgerigars also have unique connections between the auditory and motor systems. Also, analyses of the distribution of markers of neurotransmitter function in the budgerigar brain reveal patterns different from those described in songbird vocal control systems. This work suggests that songbirds and parrots have evolved separate neural 'solutions' to solve the problem of vocal plasticity. There are differences between these 'solutions' but also similarities that may be the result of convergent evolution. Although vocal behavior is learned in both songbirds and parrots, it differs in many respects. By taking advantage of this 'natural' experiment one can gain insight into the hormonal and neural events that mediate these different forms of vocal plasticity.

Animals↗
PubMed1988

Primary structure of the hemoglobin alpha-chain of rose-ringed parakeet (Psittacula krameri).

The structure of the hemoglobin alpha-chain of Rose-ringed Parakeet was determined by sequence degradations of the intact subunit, the CNBr fragments, and peptides obtained by digestion with staphylococcal Glu-specific protease and trypsin. Using this analysis, the complete alpha-chain structure of 21 avian species is known, permitting comparisons of the protein structure and of avian relationships. The structure exhibits differences from previously established avian alpha-chains at a total of 61 positions, five of which have residues unique to those of the parakeet (Ser-12, Gly-65, Ser-67, Ala-121, and Leu-134). The analysis defines hemoglobin variation within an additional avian order (Psittaciformes), demonstrates distant patterns for evaluation of relationships within other avian orders, and lends support to taxonomic conclusions from molecular data.

Amino Acid Sequence↗