We report the use of carrot, a new and inexpensive biomaterial source, for preparing high quality carbon dots (CDs) instead of semi-conductive quantum dots for bioimaging application. The as-derived CDs possessing down and up-conversion photoluminescence features were obtained from carrot juice by commonly used hydrothermal treatment. The corresponding physiochemical and optical properties were investigated by electron microscopy, fluorescent spectrometry, and other spectroscopic methods. The surfaces of obtained CDs were highly covered with hydroxyl groups and nitrogen groups without further modification. The quantum yield of as-obtained CDs was as high as 5.16%. The cell viability of HaCaT cells against a purified CD aqueous solution was higher than 85% even at higher concentration (700 μg mL−1) after 24 h incubation. Finally, CD cultured cells exhibited distinguished blue, green, and red colors, respectively, during in vitro imaging when excited by three wavelength lasers under a confocal microscope. Offering excellent optical properties, biocompatibility, low cytotoxicity, and good cellular imaging capability, the carrot juice derived CDs are a promising candidate for biomedical applications.

Neural crest and placodes share a number of important features, pointing to a possible common evolutionary origin. They both arise from the neural plate border, which is the boundary between the non-neural ectoderm and neural plate. The transcription factor Sox9 has been implicated in neural crest and otic placode induction in several species. To investigate the differential regulation of neural crest and otic placode induction by Sox9, a gain of function assay was performed using a hormone-inducible version of the Sox9 construct at different doses and time periods. Sox9 was expressed in both neural crest and otic placode cell populations in the same stage embryos by in situ hybridization. Using a gain of function approach, increased expression of neural crest marker (Snail2) and otic placode marker (Pax8) in Sox9-overexpressed embryos was observed. Higher dose of Sox9 reduced or eliminated both neural crest and placode cells in the embryos. Interestingly, otic placodes cells were more strongly affected as compared to neural crest cells. So, optimal dosage and timing of Sox9 expression are important for the development of the neural crest and otic placode. The development of the neural crest and otic placode are affected by Sox9 in a time- and dose-dependent manner.

The brachiocephalic muscle in domestic mammals is formed as a homology of the sternocleidomastoid muscle and the clavicular part of the deltoid muscle since it results from reduction of the clavicle as a clavicular intersection. The cranial insertions of the brachiocephalic muscle vary among species in domestic mammals. In the dog, the brachiocephalic muscle comprises three parts, which arise from the clavicular intersection and insert at the humerus, the dorsal cervical raphe, and the mastoid process of the temporal bone. These three parts are named the cleidobrachial muscle, the cervical part of the cleidocephalic muscle, and the mastoid part of the cleidocephalic muscle, respectively. This complexity could confuse veterinarians and complicate surgical procedures in this area. Information about the normal structure of this muscle, and any variation therein, would help to avoid such situations. During dissections of a male cross-breed dog, we found that the brachiocephalic muscle had two bellies located on the mastoid part of the cleidocephalic muscle that extended from the clavicular intersection to the wing of the atlas and the mastoid process of the temporal bone. They were innervated by the accessory nerve and the ventral branches of the second, third, and fifth cervical nerves, and they were supplied by the ascending branch of the superficial cervical artery. These bellies were considered to be a rare variation of the muscle. This is the second report of a brachiocephalic muscle variation in a dog, in which the mastoid part of the cleidocephalic muscle was made of two bellies inserted independently. Such variations should be considered during anatomical dissections and surgical procedures.

The ubiquitous Na, K-ATPase is a membrane-bound ion pump located in the plasma membrane in all animal cells and plays an essential role in a variety of cellular functions. Studies in several organisms have shown that this protein regulates different aspects of embryonic development and is responsible for the pathogenesis of several human diseases. Na, K-ATPase is an important factor for retinal development, and combinations of the isoforms of each of its subunits are expressed in different cell types and determine its functional properties. In this study, we performed RT-PCR assay to determine temporal expression and in situ hybridization to determine spatial expression of Na, K-ATPase β2 isoform (atp1b2) in Xenopus laevis. Focusing on retinal expression to distinguish the specific expression domain, we used retinal marker genes sox4, sox11, vsx1, and pax6. Xenopus atp1b2 was expressed from late gastrulation to the tadpole stage. Using whole mount in situ hybridization, we showed that Xenopus atp1b2 was expressed broadly in the eye, the whole surface ectoderm, and gills. In situ hybridization on sections revealed detailed and specific expression in the outer nuclear layer of the retina, which consists of two major classes of photoreceptors, rods and cones, surface ectoderm, pharyngeal epithelium, and gills. These findings indicate that atp1b2 may play an important role for the development of Xenopus retina.