We have developed a system for the in vitro transcription of specific genes in rooster liver chromatin by endogenous RNA polymerase II that maintains the specificity of transcription in uiuo. Radioactive transcripts synthesized in vitro were identified and quantitated by hybridization to a vast excess of cloned cDNA. The cDNA preparations employed corresponded to vitellogenin mRNA, the synthesi...

Recent studies of vocal mechanics in songbirds have identified a functional role for the beak in sound production. The vocal tract (trachea and beak) filters harmonic overtones from sounds produced by the syrinx, and birds can fine-tune vocal tract resonance properties through changes in beak gape. In this study, we examine patterns of beak gape during song production in seven species of Darwin...

Cellular and molecular mechanisms underlying differences in beak morphology likely involve interactions among multiple embryonic populations. We exchanged neural crest cells destined to participate in beak morphogenesis between two anatomically distinct species. Quail neural crest cells produced quail beaks in duck hosts and duck neural crest produced duck bills in quail hosts. These transforma...

Beak trimming is necessary in commercial broiler breeders to prevent or decrease trauma as they mature. Two common beak-trimming methods were evaluated by early performance comparison with nontrimmed chicks (NBT). The robotic electrocautery device (ECD) trims and cauterizes the beak tip. The robotic infrared beak-trimming device (IBT) applies an infrared light beam to destroy the live basal tis...

The movements of the head and beak of songbirds may play a functional role in vocal production by influencing the acoustic properties of songs. We investigated this possibility by synchronously measuring the acoustic frequency and amplitude and the kinematics (beak gape and head angle) of singing behavior in the white-throated sparrow (Zonotrichia albicollis) and the swamp sparrow (Melospiza ge...

As do many songbirds, zebra finches sing their learned songs while performing a courtship display that includes movements of the body, head and beak. The coordination of these display components was assessed by analyzing video recordings of courting males. All birds changed beak aperture frequently within a single song, and each individual's pattern of beak movements was consistent from song to...

among the major stressors in poultry that cause suffering and death of chickens. Beak trimming, removal of 1/3 to 1/2 of the beak, is a routine husbandry procedure practiced in the poultry industry, including laying hens, broiler breeders, turkey and ducks, to prevent those undesirable behaviors. However, beak trimming is a painful procedure. There is a considerable body of morphological, neuro...

The aim of this study was to determine the type lesions in birds referred clinic with complaint beak deformity, potential presence among bird species, and possible causes report what treatment should be applied. Twenty-six individuals from several species broken abnormal deformities were presented our clinics. Different forms observed, some determined as unknown. Beak wild mostly traumatic frac...

The term "parrot beak nail" describes a morphologic change of the nail plate characterized by excessive forward curvature. It may be associated with systemic disease or, most commonly, occurs as an idiopathic finding complicated by delayed nail plate trimming. The characteristics of parrot beak nails in ten men are described, and the features of this acquired nail deformity are reviewed. Of the...

The effect of removal of the lower beak on the development of the interorbital septumprenasal process (ISPP) complex was studied in chick embryos. In normal development the angle between the ventral contour of the interorbital septum and the long axis of the prenasal process increases. At the same time the angle between the ventral contour of the interorbital septum and the basal plate increase...