Copy number variants in locally raised Chinese chicken genomes determined using array comparative genomic hybridization

BACKGROUND: Copy number variants contribute to genetic variation in birds. Analyses of copy number variants in chicken breeds had focused primarily on those from commercial varieties with nothing known about the occurrence and diversity of copy number variants in locally raised Chinese chicken breeds. To address this deficiency, we characterized copy number variants in 11 chicken breeds and compared the variation among these breeds. RESULTS: We presented a detailed analysis of the copy number variants in locally raised Chinese chicken breeds identified using a customized comparative genomic hybridization array. We identified 833 copy number variants contained within 308 copy number variant regions. The median and mean sizes of the copy number variant regions were 14.6 kb and 35.1 kb, respectively. Of the copy number variant regions, 138 (45%) involved gain of DNA, 159 (52%) involved loss of DNA, and 11 (3%) involved both gain and loss of DNA. Principal component analysis and agglomerative hierarchical clustering revealed the close relatedness of the four locally raised chicken breeds, Shek-Ki, Langshan, Qingyuan partridge, and Wenchang. Biological process enrichment analysis of the copy number variant regions confirmed the greater variation among the four aforementioned varieties than among the seven other breeds studied. CONCLUSION: Our description of the distribution of the copy number variants and comparison of the differences among the copy number variant regions of the 11 chicken breeds supplemented the information available concerning the copy number variants of other Chinese chicken breeds. In addition to its relevance for functional analysis, our results provided the first insight into how chicken breeds can be clustered on the basis of their genomic copy number variation

Analysis of Pork Price Cycle and Its Relationship with CPI

Since the second half of 2015, the price of pork has come into a new round of rising cycle, especially from January to April of 2016, pork prices continued rising. Excessive rising of pork prices sparks people's concern about CPI rising. It is of practical significance to discussing the fluctuation cycle of pork price and its relationship with CPI. In this context, we do empirical research on pork cycle and price fluctuations with CPI relationships. From January 2000 to March 2016, based on a total of 195 samples, using Eviews6.0 metrology software, we draw the following conclusions: fluctuations in the price of pork did Granger cause CPI, the impact of pork price fluctuations on the CPI was significant and the effect significantly was enhanced after certain lag; CPI did not Granger cause pork price fluctuations, CPI had no significant effect on the price of pork; pork price was affected by its own large contribution, and there was a certain time lag effect of the impact; CPI had a positive impact on itself, for its contribution is relatively large. Finally we put forward relative strategies

Geological exploration theory for large oil and gas provinces and its significance

In the period of “11th Five-year Plan” (2006-2010), PetroChina proposed and developed a geological exploration theory for large oil and gas provinces, under which a group of major discoveries have been achieved. Large oil and gas provinces are large oil/gas-bearing areas consisting of several groups or belts of reservoirs (oil/gas fields) under the same large structural setting. These are determined by similar accumulation conditions, dominated by a certain type of hydrocarbon reservoir and overlaid vertically and connected horizontally. The combination of the large structural setting, favorable source rock and widely distributed heterogeneous reservoir is essential for development of large oil and gas provinces. Large oil and gas provinces are mainly developed in large structures such as continental depressions, foreland and marine craton basins, with large oil/gas-bearing areas and considerable reserves. Reservoirs are widely distributed, with low porosity and low permeability and high heterogeneity. Hydrocarbon distribution is not controlled by local structures and there is no uniform oil/gas/water contact but varying proportions of oil, gas and water. Based on the reservoir lithology, large oil and gas provinces are divided into clastics, carbonates and volcanic, which are subdivided into five sub-large oil and gas provinces, i.e. low porosity and permeability clastic; complex, steep and deep foreland structural; carbonate karst stratigraphic; carbonate platform margin reefal; and volcanic stratigraphic. Moreover, key technologies integrating seismic surveys, drilling, logging and formation tests have been developed. The exploration in large oil and gas provinces stresses the concept of “overall study, overall exploration and overall control”, and the evaluation method of “integrating exploration and development, and integrating production expansion and reserve growth”, to maximize the benefits of both exploration and development. Key words: litho-stratigraphic hydrocarbon reservoir, large oil and gas province, accumulation mechanism, geological characteristics, exploration concept, exploration metho

Formation conditions and geological characteristics of deep giant gas provinces in the Kuqa foreland thrust belt

A series of seismic exploration technologies, such as “wide line and big combination” mountainous seismic acquisition, high steep structure pre-stack depth migration processing and deep tectonic modeling, were used to explore Kuqa deep structures. Pre-salt deep structures were preliminarily confirmed and a group of large structural traps were found. The research shows that the Kuqa foreland thrust belt is favorable for forming giant gas accumulations. Large-scale imbricated thrust systems can provide traps for large-scale oil and gas accumulation; excellent hydrocarbon source conditions and later intense charges of gas provide sufficient hydrocarbon reserves; the deep mass effective reservoir sandstone works as good reservoir volume for giant gas accumulations and thick gypsum deposits serve as good cap rocks. The geological characteristics of deep pre-salt structure giant gas accumulations typically have hydrocarbon distributions controlled by structural traps and structural gas reservoirs are dominant, reservoir properties of the deep thrust belts are generally poor, with fractures being the important controlling factor for hydrocarbon enrichment, oil and gas distribution is characterized by joint control of source and cap rock, stacking of multi-layer beds, and overall beds containing gas. Reserves are large, and single well productivity is high. Key words: Kuqa foreland thrust belt, Crassus' deep beds, pre-salt structure giant gas province, formation conditions, geological characteristics, Tarim Basi

Probability mapping of petroleum occurrence with a multivariate-Bayesian approach for risk reduction in exploration, Nanpu Sag of Bohay Bay Basin, China

A multivariate-Bayesian approach has been applied to the Nanpu Sag of the Bohai Bay Basin, eastern China, to evaluate probability of oil occurrence. The geological data from 343 exploratory wells and seismic interpretations that were available at the end of 2004 were used for the purpose. Seventeen wells were drilled after the evaluation in 2005, sixteen of which reached their target horizon. Eight of the nine wells drilled in areas with a predicted high probability of hydrocarbon occurrence (>50%) encountered commercial oil, indeed; post-drilling analysis indicated that seven of these eight wells yielded high flow rates from thick net pay, and that one of these wells yielded a low flow rate. Seven wells were drilled in areas with a predicted relatively low probability (<50%) of oil occurrence; three of them were dry and four recovered oil with relatively low flow rates. Comparison of the post-drilling results with the pre-drilling prediction suggests that the multivariate-Bayesian approach can help visualize geological risk, thus improving exploration success by optimizing the drilling strategy

The multi-staged “golden zones” of hydrocarbon exploration in superimposed petroliferous basins of onshore China and its significance

The hydrocarbon generation model proposed by Tissot et al. points out the temperature and depth of “liquid HC window”, which has become a “golden zone” for hydrocarbon exploration. It has been proved by exploration that multi-staged “golden zones” for hydrocarbon exploration is commonly developed in the superimposed petroliferous basins of onshore China. There are three factors for the formation of multi-staged “golden zones” of HC exploration in the superimposed basins: (1) source kitchens developed with multi-periods and multi-centers which have verified to lead multi-stages of HC generation with large scale, (2) multi-staged reservoirs develop with large scale, (3) hydrocarbon accumulations occur with the multi-periods and late effectiveness. The conventional source kitchens, dispersed liquid HC-cracking gas kitchens and effective reservoirs with large scale join together to control the distribution of “golden zones” in timing and space. Explorational “golden zones” have the characteristics of inherited stacking and lateral variation. Paleo-highs, paleo-slopes, paleo-platform margins, and multi-period inherited fault zones control the distribution of hydrocarbons in the explorational “golden zones”. The concept of multi explorational “golden zones” helps to deepen the knowledge of new hydrocarbon distributional regularity which revealed recently in China. It shows that there exist economic resources in the deep section of the superimposed basins of onshore China. The hydrocarbon discovery history in the superimposed petroliferous basins has the feature of multi-peaks of proven reserve increase and lasting a quite long, which indicates a huge potential for future exploration. Key words: superimposed basin, multi-staged HC exploration golden zone, conventional source kitchen, dispersed hydrocarbon- cracking gas kitchen, large scaled reservoir rock, multi-period hydrocarbon accumulation, deep section, China onshor

Petroleum geological conditions and exploration importance of Proterozoic to Cambrian in China

The discovery of the giant Anyue gas field in Sichuan Basin gives petroleum explorers confidence to find oil and gas in Proterozoic to Cambrian. Based on the reconstruction of tectonic setting and the analysis of major geological events in Mesoproterozoic-Neoproterozoic, the petroleum geological conditions of Proterozoic to Cambrian are discussed in this paper from three aspects, i.e. source rocks, reservoir conditions, and the type and efficiency of play. It is found that lower organisms boomed in the interglacial epoch from Mesoproterozoic-Neoproterozoic to Eopaleozoic when the organic matters concentrated and high quality source rocks formed. Sinian-Cambrian microbial rock and grain-stone banks overlapped with multiple-period constructive digenesis may form large-scale reservoir rocks. However, because of the anoxic event and weak weathering effect in Eopaleozoic-Mesoproterozoic, the reservoirs are generally poor in quality, and only the reservoirs that suffered weathering and leaching may have the opportunity to form dissolution-reconstructed reservoirs. There are large rifts formed during Mesoproterozoic-Neoproterozoic in Huabei Craton, Yangtze Craton, and Tarim Craton in China, and definitely source rocks in the rifts, while whether there are favorite source-reservoir plays depends on circumstance. The existence of Sinian-Cambrian effective play has been proved in Upper Yangtze area. The effectiveness of source-reservoir plays in Huabei area depends on two factors: (1) the effectiveness of secondary play formed by Proterozoic source rock and Paleozoic, Mesozoic, Cenozoic reservoir rocks; (2) the matching between reservoirs formed by reconstruction from Mesoproterozoic- Neoproterozoic to Eopaleozoic and the inner hydrocarbon kitchens with late hydrocarbon generation. As for Tarim Basin, the time of Proterozoic and the original basin should be analyzed before the evaluation of the effective play. To sum up, Proterozoic to Cambrian in the three craton basins in China is a potential exploration formation, which deserves further investigation and research. Key words: Proterozoic, Cambrian, tectonic setting, major geological events, interglacial epoch, source rock, microbial rock, intracratonic rift, pla

Petroleum geological features and exploration prospect of deep marine carbonate rocks in China onshore: A further discussion

Deep marine carbonate rocks have become one of the key targets of onshore oil and gas exploration and development for reserves replacement in China. Further geological researches of such rocks may practically facilitate the sustainable, steady and smooth development of the petroleum industry in the country. Therefore, through a deep investigation into the fundamental geological conditions of deep marine carbonate reservoirs, we found higher-than-expected resource potential therein, which may uncover large oil or gas fields. The findings were reflected in four aspects. Firstly, there are two kinds of hydrocarbon kitchens which were respectively formed by conventional source rocks and liquid hydrocarbons cracking that were detained in source rocks, and both of them can provide large-scale hydrocarbons. Secondly, as controlled by the bedding and interstratal karstification, as well as the burial and hydrothermal dolomitization, effective carbonate reservoirs may be extensively developed in the deep and ultra-deep strata. Thirdly, under the coupling action of progressive burial and annealing heating, some marine source rocks could form hydrocarbon accumulations spanning important tectonic phases, and large quantity of liquid hydrocarbons could be kept in late stage, contributing to rich oil and gas in such deep marine strata. Fourthly, large-scale uplifts were formed by the stacking of multi-episodic tectonism and oil and gas could be accumulated in three modes (i.e., stratoid large-area reservoir-forming mode of karst reservoirs in the slope area of uplift, back-flow type large-area reservoir-forming mode of buried hill weathered crust karst reservoirs, and wide-range reservoir-forming mode of reef-shoal reservoirs); groups of stratigraphic and lithologic traps were widely developed in the areas of periclinal structures of paleohighs and continental margins. In conclusion, deep marine carbonate strata in China onshore contain the conditions for widely and intensively preserving hydrocarbons, so large oil or gas fields are expected

Probability mapping of petroleum occurrence with a multivariate-Bayesian approach for risk reduction in exploration, Nanpu Sag of Bohay Bay Basin, China

A multivariate-Bayesian approach has been applied to the Nanpu Sag of the Bohai Bay Basin, eastern China, to evaluate probability of oil occurrence. The geological data from 343 exploratory wells and seismic interpretations that were available at the end of 2004 were used for the purpose. Seventeen wells were drilled after the evaluation in 2005, sixteen of which reached their target horizon. Eight of the nine wells drilled in areas with a predicted high probability of hydrocarbon occurrence (>50%) encountered commercial oil, indeed; post-drilling analysis indicated that seven of these eight wells yielded high flow rates from thick net pay, and that one of these wells yielded a low flow rate. Seven wells were drilled in areas with a predicted relatively low probability (<50%) of oil occurrence; three of them were dry and four recovered oil with relatively low flow rates. Comparison of the post-drilling results with the pre-drilling prediction suggests that the multivariate-Bayesian approach can help visualize geological risk, thus improving exploration success by optimizing the drilling strategy