Phosphatized polar lobe-forming embryos from the Precambrian of southwest China

In developing embryos of some extant spiralian animals, polar lobe formation is one of the symmetry-breaking mechanisms for segregation of maternal cytoplasmic substances to certain blastomeres and not others. Polar lobe formation leads to unique early cleavage morphologies that include trilobed, J-shaped, and five-lobed structures. Fossil embryos similar to modern lobeforming embryos are recognized from the Precambrian Doushantuo Formation phosphates, Weng'an, Guizhou Province, China. These embryos are abundant and form a developmental sequence comparable to different developing stages observed in lobe-forming embryos of extant spiralians. These data imply that lobe formation is an evolutionarily ancient process of embryonic specification.     

Cancer regression and autoimmunity in patients after clonal repopulation with antitumor lymphocytes

We report here the adoptive transfer, to patients with metastatic melanoma, of highly selected tumor-reactive T cells directed against overexpressed self-derived differentiation antigens after a nonmyeloablative conditioning regimen. This approach resulted in the persistent clonal repopulation of T cells in those cancer patients, with the transferred cells proliferating in vivo, displaying functional activity, and trafficking to tumor sites. This led to regression of the patients' metastatic melanoma as well as to the onset of autoimmune melanocyte destruction. This approach presents new possibilities for the treatment of patients with cancer as well as patients with human immunodeficiency virus-related acquired immunodeficiency syndrome and other infectious diseases.     

Real time observation of mouse fetal skeleton using a high resolution X-ray synchrotron

The X-ray synchrotron is quite different from conventional radiation sources. This technique may expand the capabilities of conventional radiology and be applied in novel manners for special cases. To evaluate the usefulness of X-ray synchrotron radiation systems for real time observations, mouse fetal skeleton development was monitored with a high resolution X-ray synchrotron. A non-monochromatized X-ray synchrotron (white beam, 5C1 beamline) was employed to observe the skeleton of mice under anesthesia at embryonic day (E)12, E14, E15, and E18. At the same time, conventional radiography and mammography were used to compare with X-ray synchrotron. After synchrotron radiation, each mouse was sacrificed and stained with Alizarin red S and Alcian blue to observe bony structures. Synchrotron radiation enabled us to view the mouse fetal skeleton beginning at gestation. Synchrotron radiation systems facilitate real time observations of the fetal skeleton with greater accuracy and magnification compared to mammography and conventional radiography. Our results show that X-ray synchrotron systems can be used to observe the fine structures of internal organs at high magnification.     

Simultaneous detection of eight genetically modified maize lines using a combination of event- and construct-specific multiplex-PCR technique

To fulfill labeling and traceability requirement of genetically modified (GM) maize for trade and regulation, it is essential to develop an event-specific detection method for monitoring the presence of transgenes. In pursuit of this purpose, we systematically optimized and established a combined event- and construct-specific multiplex polymerase chain reaction (mPCR) technique for simultaneous detection of 8 GM maize lines. Altogether 9 sets of primers were designed, including six that were event-specific for Event176, Bt11, TC1507, NK603, MON863, and Mon810; two that were construct-specific for T25 and GA21, and one for an endogenous zein gene. The transgene in each GM maize line and the endogenous zein gene could be clearly detected and distinguished according to the different sizes of PCR amplicons. The limit of detection (LOD) was approximately 0.25% (v/v), although the detection can be as sensitive as 0.1% as demonstrated by the International Seed Testing Association (ISTA) proficiency test. This study further improves the current PCR-based detection method for GM maize. The method can be used in an easy, sensitive, and cost and time effective way for the identification and quality screening of a specific GM maize line.     

Genome-wide InDel marker system for application in rice breeding and mapping studies

In order to widen the genetic basis for local rice breeding programs, a set of 506 PCR-based novel insertion/deletion (InDel) markers were designed. The markers have size differences larger than 30 base-pairs and were generated by published genome sequences of rice (Oryza sativa L.) indica and japonica subspecies. Among the 506 InDel markers, 133 markers are polymorphic between the selected parents Taiken 2 and Taichung Sen 10, which are elite Taiwanese japonica and indica varieties, respectively. The InDel to amplicon size ratios, based on the japonica template, were in the range of 8.8–45.6 %, with an average of 21.6 %. As a result, the PCR product can be efficiently separated and easily scored by running 30 min of non-submerging electrophoresis on 2–3 % agarose gels. Commonly observed non-parental bands originated from heteroduplex are considered beneficial in distinguishing homo- and hetero-zygotes. A linkage map constructed solely on these markers arranged in 12 linkage groups and extended over 1,413.9 cM with an average distance of 9.8 cM between markers, based on a segregating population of 286 F₂ individuals derived from a cross between Taiken 2 and Taichung Sen 10. The result indicated that InDel markers with moderate size differences were abundant and uniformly distributed across the whole genome of rice. Due to their simplicity in design and robustness in genotyping, these InDel markers have been routinely used in our quantitative trait loci mapping studies and marker-assisted selection programs for rice. We suggest that InDel markers with moderate size differences could be a valuable alternative in addition to the widely used SSR and SNP markers for rice breeding, and particularly suitable for field laboratories at breeding stations and/or laboratories with limited resources.