铜绿蝇蛹发育形态学用于死后间隔时间推断的研究

发布时间：2018-03-16 04:09

本文选题：嗜尸性蝇类　切入点：死后间隔时间　出处：《河北医科大学》2007年硕士论文　论文类型：学位论文

【摘要】： 目的:研究不同温度下铜绿蝇(Lucilia cuprina)蛹的生长发育情况,明确其发育形态随时间的变化规律,为刑事案件中死后间隔时间(Postmortem interval,PMI )的推断提供科学依据,同时积累石家庄地区嗜尸性蝇类发育生物学资料。方法:在河北医科大学校园内以兔内脏诱捕铜绿蝇成蝇,带回实验室,在生化培养箱内连续饲养,以第三代成蝇作为母代开始实验。用猪肝诱成蝇产卵,将所产新鲜卵移置于猪肉上,分别放在16℃、20℃、24℃、28℃、32℃的生化培养箱中饲养,在以上各温度条件下,湿度(50%-60%)及光周期固定不变,食物数量维持在相对稳定的范围内。自50%幼虫化蛹开始,将蛹连同沙土移入新瓶内,每隔12h取样1次,直至半数羽化。每次皆取10头标本,用4%的甲醛固定液固定24h[1],然后放入75%酒精中保存。称量各组蛹重,用均数±标准差表示,并绘制不同恒温下蛹重随时间的变化曲线。在体视显微镜下观察蛹壳颜色,用数码相机拍照[2],用图像分析软件提取R/G/B值,绘制不同恒温下R/G/B值随发育时间的变化曲线,并做成蛹壳颜色的标准色版。在体视显微镜下剥开蛹壳,观察蛹体形态发育的变化规律,找出时间标志性特征,并据此将蛹的发育进程进行阶段划分;比较不同恒温下发育规律的不同。数据用SPSS11.5软件处理。结果: 1蛹体组织形态变化 1.1蛹期阶段的划分体视显微镜下观察到壳内蛹体组织从缩短幼虫状态到成蝇的全变态发育过程,并发现7个可标志其形态发育随时间变化的特征:Ⅰ蛹体分头、胸、腹;Ⅱ头咽骨贴壁;Ⅲ原头出现;Ⅳ呼吸角破壳;Ⅴ翅与足出现及褐化;Ⅵ鬃毛出现及褐化;Ⅶ复眼轮廓形成及色素化进程。根据上述特征把蛹期粗略划分为9个阶段: 前蛹期:虫体呈缩短幼虫状,未见呼吸角,头咽骨与蛹体组织紧密结合。隐头期:蛹前端出现凹陷,可见原头及一对小乳头状的呼吸角,头咽骨贴壁。显头期:蛹体分头、胸和腹;呼吸角呈牛角状;蛹体呈白色,全身无鬃;腹面出现足及翅;复眼轮廓形成。棕翅期:足根部呈浅棕色,翅出现浅棕色翅脉;蛹体出现浅色鬃毛,复眼黄色。黑鬃胸期:胸部背面及头部出现稀疏的黑色鬃毛;腹部沿各腹节处出现浅棕色毛;足根部变黑,翅脉呈黑色。黑鬃腹期:腹部稀疏分布黑色鬃毛;胸部鬃毛变浓密。半红眼期:复眼后半部呈鲜红色,腹部鬃毛变浓密。红眼期:复眼全部鲜红色,体鬃进一步浓密。预成虫期:复眼呈深红色,整个蛹已具成虫雏形,有膜包被。 1.2不同温度下铜绿蝇蛹的发育进程记录到达蛹期各发育阶段的时间,绘制铜绿蝇蛹的发育进程表,可得出以下结论: 不同恒温下,铜绿蝇蛹发育至某一阶段所需的时间和某一阶段持续的时间一般随温度的增高而缩短。某一恒温下蛹的各个阶段持续时间不均匀:显头期占据了蛹期相当长的时间,蛹的开始阶段和临近羽化阶段持续时间短,即形态变化较大。 2蛹壳颜色体视显微镜下观察表明,在适宜铜绿蝇发育的恒定温度下,蛹壳颜色随时间呈现逐渐加深趋势。各温度下蛹壳颜色的R/G/B数值随蛹的生长发育均呈现由大到小的变化趋势,以R值变化最明显,但此变化不均匀,在化蛹初期和临近羽化时变化较大,中间变化平缓。蛹壳颜色的标准色版可用于肉眼粗略估算蛹期及进而推断PMI。 3蛹重在适宜铜绿蝇发育的恒定温度条件下,蛹重随时间延长而减少。并且,蛹重的变化也是不均匀的:头两天下降迅速,而后趋于平缓;温度越高,蛹重随时间下降趋势越明显。结论:研究结果表明,在死亡调查时,铜绿蝇蛹可作为一种现场证据,在已知现场环境温度的前提下,可依据蛹壳内蛹体组织的形态发育变化来推断蛹期,同时结合蛹壳颜色的标准色版,参考蛹重随时间的变化情况综合分析,从而为死后间隔时间(PMI)的推断提供科学依据。
[Abstract]:Objective: To study the different temperature l.cuprina (Lucilia cuprina) growth of pupae, the morphological change over time, as in the criminal cases of postmortem interval (Postmortem, interval, PMI) to provide a scientific basis for inference, while the accumulation of the Shijiazhuang area of sarcosaphagous flies in developmental biology.
Methods: in the campus of Hebei Medical University with rabbit visceral l.cuprina fly trap, back to the lab, continuous feeding in biochemical culture box, with third generations of adult flies began to experiment as a parent. Liver induced spawning adult flies, will produce fresh eggs in pork were placed on shift at 16 C, 20 C, 24 C feeding, 28 DEG, 32 DEG C in biochemical incubator, in each of the above conditions of temperature, humidity and photoperiod (50%-60%) is fixed, the quantity of food maintained at a relatively stable range. Since the beginning of the 50% larvae pupate, together with sand into the bottle will pupa, every 12h sample 1 times, until half of eclosion. Every time the 10 head specimens were fixed with formaldehyde, 24h[1] 4%, and then preserved in 75% alcohol was measured. Pupal weight, represented by the standard deviation, pupa weight were made at different temperature versus time curves. Observe the color in the puparium under stereomicroscope, digital Camera [2], analysis of R/G/B extraction software for image rendering, different temperature change curve of R/G/B value with the development time, and make the standard color version. The color keys in the microscope to observe the changes of peel from pupa, morphological development, find the time characteristic, and accordingly the development of pupa comparison of different phases; development regularity under different temperature. Data processing with SPSS11.5.
Result:
Morphological changes of the 1 pupae
Division of the 1.1 stage of pupae
Under stereomicroscope to observe the whole process of metamorphosis shell pupae from larva to shorten the tissue of adult flies, and found that the 7 can mark the time-varying characteristics of the morphological development: 1 pupa separately, chest, abdominal wall; II cephalopharyngeal skeleton; III head; IV respiratory horn shell V; wing and foot and brown mane and browning; VI VII; eye contour is formed and pigment process.
According to the above characteristics, the pupal period is roughly divided into 9 stages:
In the pre pupal stage, the body of the insect has a short larval shape, no respiratory angle, and the cephpharynx bone is closely associated with the tissue of the pupa body.
Latent period: the front end of the pupa is sunken, and the original head and a pair of small papillary respiratory angles are seen, and the cephalic bone is attached to the wall.
Show head period: Pupa separately, thoracic and abdominal breathing; angle is horn; pupa is white, body without bristles; ventral foot and wings; eye contour is formed.
Brown winged foot roots: pale brown, light brown veined wings appear; pupae appear pale mane, yellow eye.
Black mane: chest and head back chest appear sparse black mane; abdomen along the abdominal section shallow brown hairs; foot roots black, black veins.
Black mane abdomen: a sparsely distributed black mane of the abdomen; a thickening of the bristles of the chest.
Half red eye: the second half of the eye is bright red, and the mane of the abdomen is thicker.
Red eye: the compound eyes are all bright red, and the body bristles are further thicker.
Preadult stage: the compound eye is deep red, the whole pupa has adult embryonic shape, and the envelope is covered.
1.2 different temperatures from the development process of P.
The developmental stages of recording the pupal development time, drawing from P. table, the following conclusions can be drawn:
At different temperature, the duration of the pupal development of P. at a certain stage of the time required for a certain stage and generally increases with increasing of temperature and shorten the stages of pupa. A constant temperature duration is not uniform: head period occupied the pupal stage for a long time, the pupa beginning and close to the eclosion stage continued time is short, the large morphological changes.
2 color keys
Microscope observation showed that under suitable l.cuprina development under constant temperature, puparium color with the time showed a gradual deepening trend. R/G/B values of each color with temperature puparium pupa growth showed a changing trend from large to small, the R value of the most obvious changes, but this change is not uniform, large changes in the initial stage of pupation and near emergence, change slowly. The color of the puparium standard color version can be used for naked pupa and then deduce the rough estimate of PMI.
3 pupae weight
Under the constant temperature condition suitable for the development of P.aeruginosa, the pupal weight decreased with the extension of time. Moreover, the change of pupal weight was also uneven: the first two days descended rapidly and then tended to be gentle; the higher the temperature, the more obvious the decline of pupal weight with time.
Conclusion: the results showed that in the investigation of death, Pseudomonas pupae can be used as a kind of evidence at the scene, in the field of environmental temperature is given, on the basis of puparium pupae in the form of organization development changes to infer the pupal stage, combined with the color of the standard color version of the reference, with a comprehensive analysis of pupal weight changing time thus, as the postmortem interval (PMI) to provide a scientific basis for inference.

【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：D919.1

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